Even those of us who used to await and savor Bill Cunningham’s street-fashion photochronicle every week in the New York Times—where his work appeared from 1978 to 2016—probably had no idea how precious, in time, those photographs would come to be. Cunningham had two beats: society parties and, better yet, the polychrome cavalcade of fashion as seen on the streets of Paris and, most frequently, New York.