Movies about jobs and the toll they can take on the human psyche are a tough sell. How do you dramatize fatigue, anxiety and repressed ennui without boring an audience to bits? The best approach is to use an actor’s face to carry the burden, which is what Kitty Green does in her quietly harrowing debut feature The Assistant, set during one interminably stressful workday. Julia Garner plays Jane, a recent college grad working an entry-level job at a hip film-production outfit, which evokes an earlier iteration of the Weinstein Co.