As I understand it, decline will concentrate a bit more on the lower pecs. The pic shows that you don't need it. Flat bench and inclines will give you a much better and fuller look. Pullovers (again the way I've come to understand it), work the pecs a bit differently and also help expand the entire rib cage, giving a bigger look. As stated above, your traps look a bit small. But if you've only been back into the gym for a couple of weeks, don't even worry about it. Just keep doing what you're doing and hang in there. Consistancy is the key - and diet, but you've got that down.