Apple today has seeded the new beta iOS 15.4 to developers, with a notable addition in the Face ID technology. However, it only works on newer iPhones, such as the iPhone 12 and newer models.

Currently, iPhone users can unlock their phones even while wearing a mask with an Apple Watch for extra security. iOS 15.4 has removed that authentication and makes it such that an Apple Watch is no longer needed.
Face ID unlock with a mask uses a scan of the eye area, which is less secure compared to a whole face scan. However, this eliminates the need to remove the user’s mask and risk catching a virus in the process.
The only concern is that face mask Face ID unlock will only work on newer iPhones, particularly the iPhone 12 lineup and the iPhone 13 lineup. Unfortunately, the setup option of Face ID with Mask will not be available for those who have an iPhone 11 or below.