They probably have iPhones assembled in the US by the development team at Apple. I expect they're all perfect.They are all getting on a bit now. Their eyesight is not what it used to be, I wonder if Tom Cook's iPhone has this dark blotch on his screen and whether he even notices it!
I wonder if Jony Ive looks at his iPhone 6s Plus with backlight curtain bleed and says "I love what I see! perfection!"