OK, I'm glad he did this (apart from the risk to the poor sods trapped in the car with him
).
I mean, obviously it's absurd and the behaviour of the leader of personality cult. But because so much of Trumpism involves ludicrous conspiracy theories and blaming of every ill on some unknown lizardly "deep state", I think it is actually useful that his faithful get sight of him being obviously alive since his entrance to Walter Reid.
Otherwise if he did die, the rumour would be something like: he got into that helicopter at the White House and flew to a luxury yacht which took him into exile on an island mountain top where he flips burgers with Elvis and waits for his return as the once and future king.
Fill in your own fantasy fiction here. You know the stuff, can make it up by the yard.
So although bizarre and highly irresponsible, I think his cult need these visitations to keep them calm. I suspect they'll react better if the visitations tail off slowly as he gets more ill, than if their tin god is withdrawn from them suddenly.