Everyone is missing the forrest for the trees. In the Reddit video the first brother (in green shirt) has a sizable mole on his right cheek. The other brother does NOT have a mole on his right cheek.
WTF?! If a mole isn't a facial feature that Apple is tracking, what the hell is the point of Face ID in the first place?
If these brothers were absolutely identical in every respect EXCEPT for that mole, the phone should NOT unlock for both of them, period. If that Reddit video isn't faked (switched iPhone X while out of view), then this is a major fail on Apple's part. No freaking mole recognition?!
Mark
First off, unless that mole protrudes it will not be detected. Second, why don't you know this? Do you still not understand how this tech works even though you're obviously so critical of it?