“Live-In Maid,” Jorge Gaggero’s remarkably assured first film, examines the complicated relationship between Beba (Norma Aleandro) and Dora (Norma Argentina), an upper-class Buenos Aires woman and her longtime housekeeper. The two women share a roomy apartment, which Dora keeps in immaculate order while Beba primps and sighs like an opera diva with an audience of one, or the queen of a small, secret nation. “Live-In Maid” is modest in scope, but it feels complete, fully inhabited, in a way that more overtly ambitious movies rarely do. Its story and themes are outwardly straightforward, but as the film develops, it acquires a glow of mystery, as Mr. Gaggero invites you to contemplate, within the context of two perfectly ordinary lives, the paradoxes of friendship and the challenge of maintaining dignity in a world that conspires to undermine it. — A. O. Scott, The New York Times