This is a kind of huge misinformation that only people who know nothing about Windows (and yes we are in a site of Mac users...) can believe...
You must be confusing Windows hello with the camera indentificaiton of some cheap Android tablets.
You cannot use a photo to sign in, Windows hello does not use the webcam but does a 3D scanning of the face, and it's not something that can be faked with a photo. Lidar is not the only 3D scanning soluition, there are others and Windows hello uses near infrared imaging to authenticate...