I imagine you are taking a beating on this one. Tree bark could work for this challenge. Perhaps losing the blownout portion on the right of the shot would better focus attention on the patterns in your subject. Also, the subject itself needs to be in good focus without a heavy reliance on unsharp. Further, I think you could really increase the impact (and thus the 'wow' factor) by presenting this in black and white. It might make the most out of the paterns/rhythm in the bark by highlighting the contrasts of light and shapes contained within.
the bright background is distracting. the upper part of the background has a nice strong green which is a good contrast to the bark of the tree. The tree itseld seems very soft not really supporting repetition