What has happened to my screen? 'Ink Spots' growing on Lumia 950 Screen
I have an AT&T Lumia 950, purchased it in December. About three days ago, I noticed a couple of small purple spots on the screen. At the time, I thougt they were drops of something on the screen. They weren't.
Over the last 72 hours, they've grown considerably. I've already visited AT&T and a warranty replacement is on the way - but I'm curious about what happened, and if there is anything I could have done to prevent it.

I have an AT&T Lumia 950, purchased it in December. About three days ago, I noticed a couple of small purple spots on the screen. At the time, I thougt they were drops of something on the screen. They weren't.
Over the last 72 hours, they've grown considerably. I've already visited AT&T and a warranty replacement is on the way - but I'm curious about what happened, and if there is anything I could have done to prevent it.
