Photography is well known for its capacity  to freeze time as well as movement.  The word snapshot suggests that a tiny slice of time is recorded for posterity. The snapshot takes an instant out of time, and  by holding time still it offers us an opportunity to see what  once was. The image is understood as historical in that history happens when something becomes present in passing away. 

The snapshot gives us a glimpse of the history that we have lived and it helps us to remember that history and to see how things have changed.  Snapshots of history represent the the survival of the traces of what is past and they depend on our ability to  interpret these traces  as traces embedded  in a  particular place and  our forgotten memories.

This thinking of history  relies on photography's instantaneity and immediacy, its flashlike character, illuminative powers, its appearance as a fragment or temporal shard, its ambiguous status as both an image suspended in an ever-present and a concrete artifact of the past.

Though technological advances in the photographic apparatus  suggest that that  the camera is able to faithfully represent what is before it, what is presented is a trace because  photography doesn't represent history clearly, since it severs an event, person, or object from its historical context.   

Maybe photography works best when it fails to represent. It informs us that something has sheen destroyed at the same time that it preserves  the traces and memory of what has been destroyed. In doing so it petrifies what is photographed.