> … I suppose it's simply a need to re-verify (take a new photo) upon every login …

Clearly the only foolproof solution is a 3rd-party camera pointed at your face at all times whenever you use a computer.

And a *plug to measure the heart rate at all times in the convenient and unobtrusive way, to ensure the face is of the mammal, and not the mannequin.

A sort of "telescreen" if you will.