Well because it's the shadowing on the crystals that makes it seem like the lighting is always coming from the left. The grass and stuff points outward but the character stays facing up. It would make sense if you only saw the top of the character's head. Then it'd be like looking down a well. But if that was the case you'd see the plants from the top view, instead of rotated. It's like a mixture of a lot of different perspectives.
I mean, it looks interesting though.