The rooftop of the Old American Can Company, an historic complex in Brooklyn, is packed with nearly 600 people glued to their seats. They watch the film on the large screen as the camera cuts from the gutting of a fish to broken shards of a mirror; then to Isaiah Zagar, a legendary mosaic artist, fingering colorful tiles embedded in a wall along the South Street Corridor in Philadelphia.

Inside, Clayton Patterson sits among boxes. Artwork rests propped against the walls or hangs in the darkened eaves of the room.