You enumerated so many edits in your description there's not really much of a difference between the original scan and your wall. It's just that your version looks a little darker. Probably the only improvement to the scan is that you recreated the clouds on the left and added the bokeh brushes. Those are a very nice touch. Otherwise, I'd expect you'd do more with the scan because this looks like you didn't put that much effort into it. Sorry.
And another thing is that the wall is stretched. I don't understand why you had to crop the original scan and stretched it instead. It's especially visible on the guy's head, which now looks strange. :/
I hope that you'll come up with something more elaborate next time.
