Doubt if this is a screen protector or some sort of factory film on 2DS XL

Hi all

So I got a used 2DS XL, and I have this doubt on the bottom screen there seems to be some sort of film, it’s a bit detached on the corners. Is this a screen protector someone put or does it come from the factory like this and the film is damaged?

Because if it’s just a screen protector I’ll just replace it

Thanks