Photographs seems like cruel little slices from the past, frozen images of what will never be again. Since we assume that the photographic image is, by and large, a factual view of some reality, it is inherently believed and trusted. But now be forewarned. It ain’t necessarily so. Bill Aron’s new images at the 92nd Street Y betray and beguile so as to force us to reassess the meaning of what we see.