Instead of small photos and shelves on such a big wall, I think a "feature" wall of graphic wallpaper or painting design would look fab. Not exactly this print, but something like this. But, to complement your furniture and design style. You can move the current shelves to the other wall for a collage of photo shelves at eye level.

Queensway living, Interior Design Vancouver · More Info

I agree a statement wall paper or something substantial would look better (2 huge vertical prints). The shelves next to the TV look lost on that wall