Facial recognition will recognize the feature points of the face when entering. When unlocking, as long as a certain number of same feature points, the requirements can be met. The facial feature points of twins are highly similar, and when a certain number is reached, there may be a low probability of triggering unlocking.
Basic Facial Recognition: If the phone uses basic facial recognition technology, it may not be able to distinguish between identical twins, as it primarily looks for key facial features. In this case, both twins might be able to unlock the phone.
Advanced Facial Recognition: Some phones employ more advanced facial recognition techniques, which take into account a broader range of facial characteristics and even depth mapping. With such advanced systems, it is less likely that identical twins can unlock the phone using their faces, but it is not impossible.
Machine Learning Algorithms: Phones with machine learning algorithms that continually improve facial recognition accuracy may become better at distinguishing between twins over time. However, there is no guarantee.
Face ID (iOS): In the case of Apple's Face ID, it is designed to have a very low chance of being fooled by identical twins due to its depth-sensing technology. However, it is still possible for twins with very similar facial features to unlock the same iPhone.
Security Settings: Some phones allow users to set the sensitivity level of face recognition. If the sensitivity is set low, it might increase the chances of twins unlocking the phone.
If you find anything abnormal during use, it is recommended that you send the phone to the nearest realme service center for testing.