One of the more interesting, minor new features in iOS 12 is the introduction of multi-user support for Face ID. The feature was not officially announced at WWDC, or even mentioned anywhere, but 9to5Mac reports that it is live in iOS 12 for the iPhone X.
It can be activated via a new option in Face ID settings, somewhat cryptically called “Set Up an Alternative Appearance.” The description below the new toggle is similarly vague, elaborating that, “In addition to continuously learning how you look, Face ID can recognize an alternative appearance.”
