The old users of this Apple mobile phone are a little unhappy, because it is generally believed that this is Apple's new sales method and routine, in order to stimulate the demand for changing mobile phones. But in fact, Apple's explanation is not to let everyone change their mobile phones. Specifically, it is not to let mobile phones below the iPhone 12 series use this function, but because of camera restrictions.
This is because Apple's original depth-sensing camera has developed a new algorithm, which means that only the outline of the human eye is needed to recognize the face, thus unlocking the iphone. Therefore, this requires the front camera to support depth sensing technology, while the front lens of the iPhone 12 series does not support depth fusion technology, which means that they can't let the phone only recognize the outline of the eyes by wearing a mask. Thereby unlocking the mobile phone, but the front cameras of iPhone 12 series and iPhone 13 series support deep fusion technology, so this new function can be adopted.