I'm sure you're getting blasted for too small a picture. Check the Editing for DPC in Learn -> Tutorials. Otherwise it would be a good picture. Don't be discouraged by a low score, because the size is the main reason for it.
Even though it is small.... I think that this one is one of the best. It has the dark blacks and the bright whites... It shows the challenge very well and I would have to say that this is a GREAT shot. Like I said though it is small... If you can find out how to make it bigger Then I will start to vote even higher then I did. (8)