Why were my photos rejected?

As Ralph indicated, the cutout work is not properly done, and there are obvious bits of the background in every image. When I zoom in >100% it also appears they are not all sharply focused. A couple of them also appear to be overexposed and flatly lit with no shadow detail.

I only looked at the first two photos. I donot believe that they are cut out very good. What is the dark line around the edges?