As others have stated, its display screen burn. The picture was static for too lengthy and burned into the display screen floor.
This was/has been an actual drawback for plasma screens and a few older LCD screens earlier than tech corporations realised the issue and carried out screensavers as customary.
Each display screen/television and in addition the principle system producers usually have a display screen saver mode added to their software program so it’s much less of an issue.
Relying on the depth of the burn and the way lengthy it was sitting static like that, the display screen is usually fixable by leaving it turned off for some time, to let the display screen reset by itself.
I had a hand-me-down 40” plasma television from my mother and father years in the past when i had my xbox 360. I stored a small yellow post-it notice on the nook of the display screen edge, saying “flip me off!!”
When i knew i used to be leaving my room for any period of time, i turned off my television whereas i used to be away from it so i didn’t go away a static picture. It turned behavior after some time and that i barely had an issue with it till i saved up xmas and birthday cash for a greater television that wasn’t plasma.