Sounds like you have the screen up at maximum brightness and you are seeing light bleed more than image retention (screen burn doesn't happen on LCD)
I guess what you see is the fading / transparent menu background?
For example, in Google Photos, with the menu displayed:
And after tapping the screen to hide the menu:
It's an IPS LCD, it shouldn't burn in unlike an AMOLED..
No, we mean sth like this. Please see attached picture. I used your picture and simulated this effect on a PC. I have 1) red sides and 2) you can also see the status bar (I only show the time here). It looks VERY MUCH like a burn in. And yes, it should NOT burn in like on an amoled screen. This is a problem! My phone is not even half a year old and the screen has burn-ins. I will NOT recommend a Nokia phone anymore.
It's probably a factory defect, i don't know.. you should send the phone to Nokia.
I've just tested my phone (got it somewhere october last year) with this app on full brightness : https://play.google.com/store/apps/details?id=com.cam.colortest
I can't see any burn-in, on any of the colors, just some minor backlight bleeding which is normal for an IPS panel.