3DS Screen Dark Spots

[AceOfDeath]

I bought a New 3DS XL from facebook marketplace last week, it seemed to be very lightly used and in good condition, however after testing it out for some time I noticed that the top screen has some sort of dark spots. It's in the center of the screen and is very symmetrical, and it forms the shape of a rectangle with rounded corners, with the 4 "corners" of the shape being more prominent than the rest. It is very subtle, and oddly enough displays more prominently only on certain colors, like navy blue or grey, but is essentially invisible in black or very light colors like white. It seems to be almost a sort of burn in, but the pattern is very symmetrical, it is definitely not dead pixels and I am just trying to figure out if anyone has an issue like this at all, I am assuming it's a strange hardware defect of the LCD screen. I can provide pictures if any wants an example of what it looks like, but it is very subtle and doesn't come across too well on a photo either. Anyone know what it might be?

Edit: I was able to get a very noticeable picture of it:
(It’s the black rectangle surrounding the white text, I circled it just in case)

 

[ack]

that's just how the screens are, a brightness variation is a common defect. Nothing you can do about it.

 

[AceOfDeath]

that's just how the screens are, a brightness variation is a common defect. Nothing you can do about it.

Finally a reply lol, I asked all around and no one was able to help, but if that’s all it is that’s a relief, I was just worried it’s some hardware defect that could get worse or something