That light blue puzzle piece, just below center, on the right, it's like that part of the image hasn't filled in yet - you know, like when your waiting for your browser to fill in all the images. It's so striking a difference from the rest of the image.

Provoking image.

It looked like it just dropped off on the sides. You have to look really close to see that it's the reflection of the banks that creates the illusion.

or something?

The illusion is created by the reflections of the banks in the water. It does look like ice, though, or a broken mirror.