One example is the undated photo of “a large group of unknown men, women and children standing in front of a barn by the side of the road.” Depicted are about forty people -- women in long dresses, barefoot children, men sporting suspenders -- standing in a single line the length of a dirt road, all facing the photographer. Who are they? Where are they? And why are they lining the road in a single line? With or without identification, Mr. Warner’s photos leave a lot to the imagination.