iPhone Notification Tells You Apple Watch is Unlocked
I only started noticing this notification after installing iOS 14.5. The Mask Unlock feature is also turned on. However, while that allows you to unlock an iPhone whilst wearing a mask, this is about the Apple Watch being unlocked. This new notification appears both when the passcode is entered or sustained movement unlocks it. For completeness, I’m using an iPhone 12 Pro and Apple Watch SE, both running the latest public (not beta) versions of their respective operating systems.
It’s hard to immediately think of many practical uses for such a notification (although please feel free to share any you can think of in the comments below!), beyond perhaps alerting a user if a misplaced/stolen Apple Watch is being used by somebody nearby. However, it is a further, nice, demonstration of the close integration of the two devices and their operating systems.