No movie this year has made a more powerful argument for unplugging than “Jawline,” a disturbing, darkly hilarious documentary on live-broadcasting influencers. In this market, aspiring teenage social-media stars chase fame while their followers seek a shoulder to lean on (perhaps especially in situations when parents or mental health care aren’t available). Adults circle, ready to exploit any profits.

The director Liza Mandelup’s entry point into this world is a young man from Tennessee: Austyn Tester, who was 16 at the start of filming. Coiffed like Justin Bieber (they all seem to be), he logs on to the website YouNow and, in video chats, encourages members of his virtual claque — mostly adolescent girls — to pursue their dreams.