I think you need to spend a little less time in the company of conspiracy theory nuts Spud.
Just listen to yourself - you've jumped to a conclusion and you are desperately trying to make up stuff that isn't there.
The brightness of his hands and hers may not be strong evidence, but the finger 'stuff' as you call it certainly is there. Why would someone try to make a finger look longer? The only reason I can think of is to make it look like he is groping her. If so, then we have a motive: the faker is trying to frame him.
There is no credible evidence to suggest that the photo is anything other than genuine.
The shadows from Virginia should, according to one Youtuber, be semitranslucent. and wider, since she is pictured as standing quite far from the surface they are falling on (the window).
There is also the problem that the far left wall is brightly lit, with all the detail of the banister visible. But when you look between Virginia's legs and between her legs and Ghislaine's, There is very dark background with no detail. Why are those areas not illuninated, indeed why can we barely make out Ghislaine's legs if the flash illuminated the left wall so brightly?
Edit: In fact, The detail in the two white walls on the bottom left and bottom right of the picture are clearly visible. But the region in between the walls (the legs of the three people) has been obscured by some kind of smudge.