Installation view of “Siena: The Rise of Painting, 1300–1350,” on view Oct. 13, 2024–Jan. 26, 2025 at the Metropolitan Museum of Art in New York (photo: Eileen Travell, courtesy of The Met).

Although it encompasses only 11 paintings, “Alone, Together: Viewpoints From the Corcoran Legacy Collection” does invite multiple perspectives. The artworks in the American University Museum ...