It has determined a number of faces (as you would expect from any facial recognition software) but it has also figured out the names, despite me never having entered any
MacOS – How has OS X’s Photos app determined people’s names under the ‘Faces’ album
#face recognitionmacosphotos.app
Best Answer
It has access to the face data in your contacts, such as from syncing with Facebook. So, it's found similarities to those pictures.