Apple in iOS 16 updated the battery icon on iPhones with Face ID to display the specific battery percentage rather than just a visual representation of battery level. At launch, this feature did not include the iPhone 13 mini, iPhone 12 mini, iPhone XR, or iPhone 11, but according to multiple reports from the MacRumors forums and Twitter, all of these iPhones now support the feature.

Battery percent was not present on iPhones that have ‌‌Face ID‌‌ in iOS 15 because of the lack of space on either side of the notch that houses the TrueDepth camera hardware, but Apple's updated ‌iOS 16‌ design adds the specific battery level to the battery icon, providing a better idea of battery status at a glance.

With this update, ‌iPhone 13‌ mini, ‌iPhone 12 mini‌, ‌iPhone‌ XR, and ‌iPhone 11‌ users can see their battery percentage in the status bar, and battery percentage is officially available on the ‌iPhone‌ XR and later. Devices without a ‌Face ID‌ notch always display the battery percentage as well.

Source: Macrumors