My 6S has a darker bluish tint on the upper left quarter, I'm deciding what to do, if to risk for an exchange etc.
But that dark corner you have is even worse, I've seen it already here but I don't think it should be considered normal. Personally I would have it exchanged.
But that dark corner you have is even worse, I've seen it already here but I don't think it should be considered normal. Personally I would have it exchanged.