An overturned truck on the steps of San Francisco’s Yerba Buena Center looks like an accident has just happened, and has prompted passersby to call 911. “Open at the back, the truck holds about two dozen video and computer monitors, some of which flicker with chopped-up animation, scrambled convenience-store surveillance tapes and footage of a man rolling paint over graffiti on an outdoor wall. The man has a Sisyphean counterpart in real space: a mechanized wood cutout figure who brandishes a spray can up and down, up and down, reminiscent of Jonathan Borofsky’s famous Hammering Man.”