Because a photograph is already a lossy simulation of some real situation. But then, even though we don't know what WW1 or Marilyn Monroe really looked like, we know what the artifacts look like. Upscaling is yet another level of simulation. What it says beyond the immediate impact is more about the early era of deep learning than it says about WW1. But it also entices us to mistake this Disneyland WW1 for something that's supposedly behind the original artifact (which did have some reference to the real battle). This is what Baudrillard calls the hyperreal.