I remember that the version of the Macbook Air with an Apple symbol light on the casing. It has the unfortunately flaw that over time the light burns into the screen, it looks like someone has put a large mug of hot coffee on the closed laptop...
The light doesn't permanently 'burn in' as you describe, but if there's sunlight shining directly on the back of the laptop I can see a (very faint and blurry) outline of the logo on the screen. Putting a sticker over the logo would fix it, I suppose, though it's rarely noticeable. (If the light's bright enough to shine through the screen, it's also bright enough that I'm squinting into the sun and wanting to sit somewhere else.)
> If you carry laptop around and it's squished between books or whatever, that's how you get that. My first unibody macbook developed this issue. Now I use a hard case.
> What I suspect happened here is you had laid something heavy on top of your air so the logo disk in the lid embossed the defuser sheets.
...etc.
https://www.ifixit.com/Answers/View/256877/Why+do+I+have+a+c... https://www.reddit.com/r/mac/comments/7ph5bi/apple_logo_ligh...