“Van Dyck focused on the subject’s attitude toward being in the picture, a joint venture of artist and sitter that continues to this day as a model, or a foil, for artists like Kehinde Wiley, Elizabeth Peyton, and Cindy Sherman. We might include earlier practitioners as well, like Lucien Freud and Alice Neel, or, to cast a wider net, photographers Cecil Beaton, Irving Penn, and Richard Avedon.”