I'm going to try to upload a pic of myself from a winter 3D shoot. This was just warming up (literally it was about 20 degrees out)so I'm not sure if it's my best effort but it's the only picture I have of myself shooting.......I think it will give you a good visual of body position.
Release type is different but it's the same concept on form.

One thing I noticed on your picture other than what was already said is the tension in your hands, relax them and your forearms. (Think "dead spider" on your hands, just let those fingerscurl down naturally as if dead)
Think of your bow arm as a 2X4, just set it and forget it. That arm is just relaxed resistance against your pulling through the shot with your release arm via the back muscles. Keep the tension of the shot behind your shoulder.