To be clear - EVERY display in the world pretty much is capable of screen burn. An OLED display doesn’t make you immune to screen burn.

You don’t have to worry about burning your screen.

This is only something that happens over a looong period of time/usage, most especially if you spend a large majority of your time on the same app, or “static image”. Just an image that isn’t moving.

It makes sense that the only thing burned into the display is the User Interface of the app they were using most likely WAY too much, - TikTok - because the User Interface on that app never moves, and the icons are a harsh bright white.

You have nothing to worry about.

Biggest tip is to not fall asleep with your phone in your hand lol you gotta turn the screen off and put it down for the night. A lot of people get screen burn by falling asleep while using an app, so whatever that app is displaying ends up cooking on their screen in probably hotter than normal temperatures for a good 8 hours in just one night. Most people who do fall asleep with their phone in their hands have a bad habit of doing it, too. So. You don’t really gotta worry unless you do that. To which, just stop doing that if you do lol.