In 1995, Harmony Korine—then an eighteen year old NYU freshman—was tapped by the photographer and filmmaker Larry Clark to pen the screenplay for what would become his breakthrough hit, “Kids.” The film is driven by a wonderfully efficient set-up: Jennie (Chloë Sevingy) needs to track down Telly (Leo Fitzpatrick) to explain that he’s probably infected with HIV, but she has no idea how or where to find him. The ensuing search involves skateboarding, skinny-dipping, drug deals, and finally a house party. Not only does it provide an opportunity to shoot in a wide variety of Manhattan locations, it also generates tension: will Jennie find Telly before he sleeps with another girl? In a 2015 interview, Korine lamented the fact that “Kids” could never be made today. Jennie simply would have called Telly to deliver the bad news. This raises an interesting question: are there instances in which, for the sake of dramatic effect, characters in contemporary films should not have access to mobile phones?

There is not a single cellphone is Damien Chazelle’s “La La Land.” This absence seems consistent with the film’s gleefully analog aesthetic, but it creates a handful of logistical hiccoughs. Take, for example, the sequence in which Sebastian (Ryan Gosling) invites Mia (Emma Stone) to a screening of “Rebel Without A Cause.” Mia accepts the invitation, forgetting she has a previous obligation with her boyfriend the very same evening. Under ordinary circumstances, this would be no problem—text Sebastian, apologize for the confusion, and ask to reschedule. Instead, Mia stands him up. This uncharacteristic lack of communication—there is no reason to assume that Mia would deliberately offend Sebastian—provides Chazelle with fodder for a few poignant shots. First, Sebastian pacing dejectedly in front of the marquee and then a heartwarming reunification when Mia decides to abandon her dinner and join Sebastian at the movie. In other words, the filmmaker recognized he could create greater dramatic impact if the characters were unable to communicate and so he elected not to give them cellphones and instead squeeze every last drop of melodramatic pulp out of this goofy and improbable set-up.

If all this seems persnickety, consider an earlier sequence in which Sebastian regales Mia with a tip about how to increase the range of an electronic key fob by holding the device to one’s chin. How can the screenwriter justify chitchat about an electronic car key while pretending like cellphones don’t exist? La La Land’s pick-and-choose approach to contemporary technology is frustrating and unnecessary. Every storyteller should to be granted a certain degree of leniency but even the most far-fetched of tales ought to conform to its own internal logic. The tools available to a character should be consistent with the time and place in which the story is set.

Olivier Assayas “Personal Shopper” explores the set of narrative possibilities offered by cellphones rather than bemoaning the fact that technology exists at all. Maureen (Kristen Stewart) works, you guessed it, as a personal shopper for Kyra (Nora von Waldstätten), a wealthy socialite who requires a ever-expanding wardrobe in order to preserve the glamorous figure she cuts at fashion shows and other exclusive events. Maureen is responsible for picking things out, determining whether they’ll fit, and shepherding the clothing to Kyra’s Paris apartment. She is in near constant communication with her boss, though the majority of their correspondence takes place over the phone. They meet in person just once, but even then Kyra is distracted by another phone call—this time with her lawyer to discuss the fate of a chimpanzee donated by her family foundation. Maureen and her boyfriend, an engineer stationed in Oman, conduct their relationship along similarly distant lines. They communicate infrequently via Skype and seem to begrudge even this modicum of contact. The film provides a subtle commentary on the loneliness of modern life, arguing that mobile technology has made life more solitary in spite of the supposed connectivity it affords.

Maureen is a reliable employee though her professionalism is betrayed by a compulsion to try-on Kyra’s clothing, a practice that is strictly forbidden. In much the same way that a kleptomaniac is motivated by the act of thievery itself, Maureen revels in the perverse thrill of wearing her employers clothing without permission. Her pleasure is derived from the transgression but also from the opportunity to imagine herself as Kyra, to participate in a glamorous fantasy, at least temporarily. So when a shopkeeper asks Maureen if she’d like to try a pair of extravagantly pointed heels, she has a hard time saying no. Maureen slips on the shoes: a perfect fit. This is something of a glass slipper moment. Seen from a certain perspective, “Personal Shopper” looks a lot like a contemporary recapitulation of “Cinderella” in which Maureen plays the virtuous princess relegated to a life of senseless hard-work while her wicked companion enjoys an opulent lifestyle. But “Personal Shopper” is no fairytale and the film has neither a prince charming nor a particularly happy ending.

The vast majority of Maureen’s billable hours are passed in transit: from one boutique to another, from Paris to London and back again, etc.. She spends much of this time researching various things on her phone. What, exactly, does she research? Now would be a good time to explain that Maureen considers herself a “medium.” She believes that her body is a medium through which she can communicate with spirits (living and dead). The principal reason for her being in Paris is in order to establish contact with her recently deceased twin brother Lewis, who lived and worked in the city and recently passed away due to heart complications. Assayas draws a parallel between Maureen, her spiritual capacity, and a handful of notable artistic figures such as Victor Hugo and Hilma af Klint, a Swedish modernist painter, who were said to possess similar convictions. The director cleverly accomplishes this by having Maureen watch YouTube videos detailing the lives of these artists during her habitual commutes. For example, we’ll be given a shot of Maureen alone in the metro, staring at her iPhone, white ear buds plugged in. First, we’re struck by the sense of isolation, the shot communicates this much on its own. Yet, the audio is the audio of Maureen’s headphones, rather than that of the train interior, and the shot is interspersed with close-ups of the cellphone, so the audience simultaneously receives supplementary information about the artist as we gain an appreciation for Maureen’s loneliness. Though the information is relayed inventively, I question its relevance to the film. These interludes come closer to digressions than essential contributions. They distract, rather than supplement the film’s central narrative.

Cellphones are used most successfully during the film’s best and most suspenseful sequence. Maureen is travelling from Paris to London via train for work. In the waiting lounge of the Gare du Nord she receives a series of ominous and threatening messages from an unidentified sender. The man appears to know a great deal about her personal life and travel plans. First Maureen is intrigued, then perturbed, then terrified. Assayas exploits the unique dramatic potential of a conversation carried out over text message: it is possible to conceal the identity of one of the participants over an extended period. This is a trope of the horror genre—the unidentified caller—updated for the era of 4G LTE. Suspense is derived from our not knowing who is on the other end. The sequence is particularly unnerving because it is familiar. Each of us has experienced the anxiety and apprehension of sending and receiving crucial text messages, thus we are acutely sensitive to its screen portrayal.     

Enough about phones. “Personal Shopper” excels because of its leading lady’s performance. Kristen Stewart, who is something of a muse for Assayas having co-starred in his 2014 film “Clouds of Sils Maria,” is captivating as Maureen. She plays the role a bit like Clarice Starling (Jodie Foster) in “Silence of the Lambs,” vulnerable upon first impression but bold and intrepid when she finds herself thrust into violent circumstances. The film is tonally similar to another 2016 French thriller with a female lead, Paul Verhoeven’s “Elle,” but where that film shocked, this one scares. “Personal Shopper” has the slow-burn of a Michael Haneke film, or perhaps a less-stylized David Lynch project.

Other elements fall short. Fans of the Norwegian writer/director Joachim Trier will be excited to see his frequent collaborator, the actor Anders Danielsen Lie (Oslo, August 31st), in a rare English speaking role, but his character feels unnecessary and poorly conceived. Assayas, who is French, is credited as the film’s sole screenwriter and the English dialogue has a tendency to feel clunky and run long. These minor critiques take nothing away from the film’s intensity however. The curious combination of fashion and occult combined with Ms. Stewart’s tremendous lead performance make “Personal Shopper” a film worth seeing.