Pixels get stuck in a certain position…
if you leave an image on an LCD display there long enough… you will see it “burned in” to the screen…
I’ve done it before, i went away for 3 days, left my monitor on without a screen saver and saw the logon screen when the screen was white… if you leave the screen white for a couple of hours it was wash it out… or if you get a pixel program that flashes multiple colors fast to get the pixels “unstuck”