I'm no expert, but I would bring the rocks on the right forward a few inches. Having them on the same plane (at least, they look like they are) makes it look a bit contrived, but again I'm no expert, just my personal opinion.
Hard to tell if you've done so already, but if not, I would slope the substrate so it's higher at the back, and like Jason said, definitely move the rocks on the right forward. If the substrate is raised at the back, it will give the tank more depth, and the rocks on the right will be lower when you move them forward down the hill too, which will also make a big difference. Don't change the positioning or angle of either group of rocks though! They look great!