@Background Pony #4423  
So it originally didn’t have the ‘cut off’ bits? In that case, kudos to you for adding them and making it look seamless.

Not op but I am the guy who did the wallpaper edit adding the foreleg and the rest of the cut off bits. It was already edited when I got to it featureless crotch, but I cleaned that up a bit further as well. This image has changed hands quite a few times by now. Good job to the original artist. Op’s crop is fine too, looks better without all the blank space.

@dt  
The first one, why someone might want to edit it isn’t rocket science. The second one cuts off parts of Derpy herself. Another version that’s (a) just Derpy without the extra empty space, and (b) is at least not as far into “things you really wouldn’t want on your screen when someone else came in” territory doesn’t seem to exist.
 
And even if it did, I can’t see how it’s the end of the world. If it were actually a pointless duplicate of something, it’d get merged eventually.
 
And if it wasn’t? Well, in a site with over one million images, one that you could say isn’t strictly necessary exists. Celestia preserve us, the end is neigh. :p

@Phantom Rider  

@dt  
I don’t blame him/her if what was cropped from the original was just empty space.
 

Is this your thing, OP? You find pics here you like, crop them, then repost them?

The bubble butt is so damn real…