Be more confident, you look great. Feel as if you are the winner, it will show during your posing. Don't forget to smile while you pose as well.
Your back has good thickness, and width, once you lean down more in the next few weeks, it will look even better.
As someone has already stated, you are close to National level size. You look to be about Skip Lacours size, heck I'll go as far to say, with better quads!