Screen stain, burnt or wet?

[chinchillas]

Howdy. I just bought a second hand iPhone 6S and it comes with a weird stain where the arrows point. Do you think it's an issue of a burnt circuit or is the screen wet?

 

[JPack]

I doubt it's a burn because the LED backlight is mounted at the top of the display.

Could just be a replacement display with poor lamination.

 

[chinchillas]

I doubt it's a burn because the LED backlight is mounted at the top of the display.

Could just be a replacement display with poor lamination.

I'm going to return it anyway :/