Céline Sciamma, writer and director of “Portrait of a Lady on Fire,” calls her period film a “manifesto on the male gaze.” This is the most accurate, elegant description of her story of a romance between two French women in the late 1700s. This is an impeccably detailed, beautifully acted, refined drama with a strong feminist angle that’s as stirring as it is thought-provoking. Marianne (Noémie Merlant) is commissioned to paint the wedding portrait of Héloïse (Adèle Haenel), a young woman who has just left the convent. Because Héloïse is a very reluctant bride-to-be, Marianne arrives under ...