Although some images may fit into more than one catagory, usually they will fit best in one. In the photography gallery for examply i see (and have submitted myself) some "borderline" photos that have been tweaked in PS or some other program. I think basic bright/contrast/and some color saturation adjustment is fine, because I believe these techniques are common photolab techniqes that can be applied to any image, and they dont obscure the original photo, like adding lightning. But what about combining two original photos, and blending them together in the middle, would that be a 2D or a photography submittal?