It’s a sight familiar to anyone who’s been nurtured on a steady diet of international films: Children are sitting in a classroom, getting lectured by an irate teacher. The conversations are in Farsi, which suggests we’re somewhere on the outskirts of Tehran. The fact that one of the students is dressed as Groucho Marx signals we’re not in Kansas anymore. Eventually, the camera leaves the school grounds and begins to follow two sisters; they’re played by nonprofessional actors Rojina Esmaeili and Saba Vahedyousefi, and exhibit...