Zoe Strauss shot this photo in 2001 and it is now in her solo show at the Philadelphia Museum of Art. Strauss, an art activist and self-trained artist, does classic American street photography, with a difference: Before being shown in art galleries, her pictures were mounted in annual shows in an abandoned space under I-95 in South Philadelphia, where they were on sale for five dollars. Strauss goes some way toward bridging the troubling gap that’s always existed between elite art photographers and their humble subjects.