First of all, understand that I'm looking hard for stuff to criticize. I like the idea all in all but here goes...
1. Skin blotches between right buttock and hip
2. Minor imperfection in lip of cement pedastal slightly off-center to right
3. Entire image is slightly off-center to left
4. Thighs would have looked better if her knees were raised higher so the muscle didn't sag over edge of pedastal. Alternatively, seat the model further back on the pedastal so that the "sag" isn't seen by the camera.
Like I said, I had to nit-pick to find those. Good job of thinking outside the box.