Actually with many designs (and this really print) the photo could be the main center of attention. In fact a custom photo should communicate the concept of the design, not just illustrate it. So just think of the difference between say a cover photo on a magazine (like an Entertainment Weekly issue with a real Hollywood Star) vs. the generic stock photo. So the photo should be everything -- and the same with the interface and art direction of a website.

I never thought about that... Perhaps I need to take some design courses :D

Forget design -- take an art history course! that's the foundation...