Wow...I'm speechless.
Time to back out of this thread slowly and thank dog I don't have this disease that the rest of you have.
When I first opened this thread, I thought everyone was nuts. But then I looked at my 6S Plus and found the same imperfection. On mine, it's not a big deal. Not even a small deal. But if it was a little more noticeable (as has been reported on some people's phones), then I'd probably be complaining.
My goal and reason for posting in this thread is to support OP and others in evaluating the scope. A big question is if this is a batch imperfection that can be corrected with a replace/repair, or just something in the design that impacts all 6S Plus devices.
Laughing these people off as diseased (as you put it) — that attitude doesn't help anyone.