How you answer depends upon the depth of your curiosity, or one might imagine, the depths of your desperation. However, there is, for some, a profound meaning in the relationships shared between different views of similar objects. Call it the cumulative force of identical items grouped a force willed into existence by the necessity of compulsion, which is embodied best, of course, in the collector.
Collectors are, after all, closet curators and vice versa.
These visual examples record and expound upon particular instances in time and history. They are heroic in their specificity, blind in their prejudices. The fact that the makers of the pictures are not identified almost gives the images an air of myth, or non-realness, as though they were documents of some parallel world. No other medium can capture death and atrocity as ably and as horrifically as film. And as found by collectors dedicated to discovering them.