I recently bought a "new" 1.1 Nintendo Switch and I immediately noticed a "problem" that I also had with my previous machine. Basically, you can see a bunch of scanlines-like thingies on the screen, sort of like the ones that appeared on old TVs. These ones are extremely thin and highly translucent, though, so it's hard to notice them at first, but once you do, you cannot unsee them. It's easy to spot them when the screen is in motion or in games with vibrant colors and high contrast, such as Breath of the Wild and Dragon Quest XI.
It's not possible to record them or photograph them, unfortunately, but they look kinda like this:
Curiously enough, this only happens for like 5-10 minutes on the new unit after being turned on, then they vanish. Or I don't know if I just get used to them or something. The other Switch had them permanently, and I ended up sending it to Nintendo, and such replacement has never had any problems to date.
At this point I don't know if I just have very bad luck or this is just a byproduct of cheap LCD screens and I should expect this to be present in most units. As for my Switch, I think I can live with it as it is right now. Hopefully the scanlines don't become permanent.