I agree with the above. I think you got carried away in using too many stocks.

One of the biggest tell tale signs it was photoshop is lighting! MAKE SURE that your lighting stays the same throughout the piece. and if it doesn't get rid of it for something else, and if you can't do that try and cover it with something, or make the shadows and highlights more neutral.

Not bad kinda cool, but not realistic at all and looks more like a collage.