I've heard this critique before and it seems to apply, if you want to keep the focus on the plant containing the person, soften the top edge of the picture so that the eyes come back to the focus. Also I think a wide view of this picture without as much of the wall (going up) would be more flattering, but, I could be wrong, you'll have to use your judgment on that. I love how the bush is sorta eating the person, and I love how the bush has a hand extending up the wall. I also see he has a head, which is great, the vine thing almost reminds me of one of the bad guy characters on Toy Story, lol. Quite fun One thing that would be cool to try is standing on a ladder and looking down. Instead of the wall appearing to curve away and backwards, it might appear to curve in to the model.
The ivy in this shot reminds me of a shadowed figure creeping up on someone with his outstretched. And then the subject's hands would be like binoculars. I don't know, I just get a kind of 'Look out behind you!' vibe from this picture.Very neat idea and execution!