You can see in the original she's cleanly shaven, the lighting along the right side of her stomach and breast isn't that bright, and that her areolas don't seem to be quite as big as the shopped one shows them as.
The original version of it is very real- just with black squares over the fun parts.
If you want to spot the most obvious photoshopped area, I'd say the outside of her right breast looks way too sharp. Photoshopper should have blurred that just ever so slightly.
This is a fake. A very good one. There was a collection of fakes for NDN in the last week or so and they're all very well done. And the comment about the PS breasts looking too perfect...gotta disagree, the person who did this did a very accurate rendering IMHO.