I think GeForce's pic is referring to the clock digits clearly burned into the screen, not the moire.
Burn does happen.
My Note 4 got screen burn from my browser, Opera from the top bar and lower buttons and became increasingly visible after nearly a year.
Luckily it was covered by warranty and my phone came back looking like new.
I now use a full screen mode browser.
I remember arguing about the severity of screen burn here last year with someone, they were saying samoled burns under four months and I was calling BS.
I guess under some circumstances, burn could happen.
So I kinda apologise.
My guess is if you leave any contrasty Image on a screen for long lengths of time, regularly, you'll get burn in, which in my personal example, is what happened to me as I use my browser constantly. Shop display models are going to suffer to obviously, maybe that's why samsung usually have some kind of demo running?
I had screen burn on my S2 (also opera) also but it wasn't as bad. I even pointed it out when I sold it.
That all said, I prefer samoled to lcd.
I think Apple will use amoled when the price is right.
They'll want to maximise profit from it and last time I read anything about it, lcd was cheaper than omled by quite a bit.
Makes sense to keep using lcd.
Come to think about it, what's the cheapest tech item with samoled?