Yes, I think this is an artifact of the new under-display camera (at least on the inside). The official copy states:
> iPhone Duo uses Touch ID, which is integrated into the side button. This gives you an easy, secure, and consistent way to authenticate iPhone Duo, whether it’s closed or open.
Probably no way to do FaceID from under a display yet.
And thank goodness for that. I loathe, hate, despite, reject Face ID. The Duo is too pricey for me, but Touch ID makes me reconsider.