Well, if this has indeed been photoshopped all over the place, that would actually be quite a big story.
However, since there is no plausible reason to do that (is the claim that all of these bits of shoe and cardigan have been changed to hide lashings of blood and vomit?), what is weird is making out that things that probably have a trivial explanation, and concern inconsequential parts of the photo even if they had been changed, are important.
I suppose there might be something to that argument if photoshopping was some kind of messy process. Like, you change Kate's face to make it look not bloated or whatever, and that causes strange effects to happen elsewhere. But that really isn't how it works. People who think this photo shows Weird Stuff™ need to explain why anyone would decide to chip off a bit of a shoe, which would incriminate the whole photo for no reason at all. Again, unless the claim is that the photoshopper is trying to give us all super-subtle clues that only random MNers can spot, at which point we're firmly in tinfoil hat land.