Here are some pictures:
These were taken with my Nexus 7 2013 so excuse the poor quality. I removed my screen protector prior to taking these shots.
All the color screens are from Dead Pixel Test. I've also included a snap of gmail and circa just to illustrate the blotch in apps with light backgrounds.
I try to be as careful as I can with my phone. I've never dropped my phone on the ground or in water.
I found this article while I was searching - it looks similar.
What kind of damage is this?