No, he’s not just urning his head from to side to read (haltingly, because he’s functionally illiterate) the teleprompter. He can barely face America head on, or maybe he can’t control his head movements or he’s too dilapidated to hold up his head. Those weird, wandering head slumps may also in some way indicate that he knows every word he says is a lie, and he’s tired of having to go through the same sham motions over and over again. The twitchy, spastic temper of those movements is a further sign of his condition.
We could go on.