I'm going to compare Po's wall with yours.....
Honestly, I like Po's version better. Only for the reason that it's a bit more 'mature' (cant think of a better word). I guess it depends on your audience, and who you really want to appeal to. Your's, TBC, is more of a fun look at ghosts, and Po's is a more realistic looks at them....which I personally prefer.
On a more technical note, Po's wall has a better background, because it has better lighting. I'm not knocking your photo in the least! There is just more contrast between the background and foreground in his, which I think is a bit more interesting. There is more depth to it.
Also, I think your ghosts should vary more in transparency from each other, Which would also give it more depth.