I have to start with saying I hardly know anything about smart phones. I don't have one. The Dutch Consumer Organisation "Consumentenbond" has recently published an article (in Dutch) in which it says that the face recognition to get access on a smart phone can be fooled by using a photo. The article gives a list of smart phones on which it can be done and on which not, according to their test. Article in Dutch: https://www.consumentenbond.nl/veilig-internetten/gezichtsherkenning-te-hacken If I didn't use here the right words, I apologize!
Full frontal vulnerability: Photos can still trick, unlock Android mobes via facial recognition Dutch consumer club names 42 easy-to-fool cameras January 4, 2019 https://www.theregister.co.uk/2019/01/04/photos_trick_smartphones/
