I was wondering the same thing. It's due to how LCDs refresh, top to bottom, line by line. Given the fact that our display is so dense with pixels, and the GPU isn't extremely powerful (it's a tablet after all), this is bound to happen.
It also happens on iPads, so don't think it's exclusive to the N10.
Sent from my Nexus 4 using xda app-developers app
HTC G1 | HTC G2 | Galaxy Nexus | Nexus 4
Nexus 5 | Nexus 10