Deceptively complex and uncommonly elegant, “Was She Pretty?” is a series of gorgeous line drawings, most of men and women. Each is accompanied by a sentence or two describing something — some spare fact — about someone’s ex. “Hugo’s ex-girlfriend Katya was 70 percent deaf. She had a gentle way with children and animals,” reads one page. “Katya’s ex-boyfriend never stopped sending her postcards,” Shapton writes on the next. Together, these brief encounters with the other tell a story about the difficulty of accepting that those we love have loved before — and of recognizing the ugly truth that they may love again.