Céline Sciamma's “Petite Maman” runs a mere 72 minutes and yet packs a lifetime of enchantment.

This image released by Neon shows Nomie Merlant, left, and Adle Haenel in a scene from "Portrait of a Lady on Fire." (Neon via AP)“Do all lovers feel they’re inventing something?” asks Heloise, a young woman experiencing romantic passion for the first time. “Portrait of a Lady on Fire” is a story of unexpected passion between two women. Female artists of the time, Sciamma has explained, produced work that hangs in museums around the world — and yet the outside world knows very little about them. When the mother leaves for an extended trip, the three women — Marianne, Heloise and maid Sophie — are left on their own, forming new and surprising bonds that transcend both convention and class.