“Nona Faustine: Ye Are My Witness” White and black find new symbolic and historical meaning in Nona Faustine’s work. The show takes its title from a 19th-century Brooklyn slave owner’s diary and continues Ms. Faustine’s project of photographing herself nude, wearing white pumps, in sites throughout New York City linked to its slave history. White portrait busts of Thomas Jefferson and George Washington, altered with nails and soil, remind us that Jefferson owned and employed slaves in his blacksmith shop, while Washington’s enslaved labor tilled his tobacco plantation.