One thing that I notice right away, but this is not what was mentioned in the rejection note so may be completely irrelivant, is that on the example you've shown that was accepted, the border is a very nice added element to the file. The whitespace on the other throws me off a bit. I am a big fan of whitespace, but there seems to be a lot at the bottom and the sides. I am not suggesting to add the border, just maybe crop off some of the whitespace. Your man is very small in comparison to the size of the composition than in the accepted file you've provided.