Photographers have long been trained to approach their subjects from the front. But in a new exhibition at the Pace/MacGill Gallery in New York, each portrait curiously has its vantage point set from behind. What it uncovers is a long overlooked tradition of portraiture that flirts with the power of mystery and provokes questions over an often-neglected feature: the back. “The architecture of the back is phenomenally interesting and beautiful,” says Peter MacGill, the founder and president of Pace/MacGill Gallery and the show’s main curator.