Looks like a mini stroke..seriously this guy should have retired a long time ago
TIA or possible a febrile seizure, COVID part 27 is going around DC (has reverted to its original gut bug orientation, nasty but not life-threatening unless you are as old as Mitch).
He looked jaundiced and notably he made the amateur mistake of staring into the MSM camera light. That is the first thing you learn behind a podium do NOT stare into that light, your pupils will contract and your brain will interpret that as, metaphorically, "oncoming train" and put you into fight-or-flee mode. The resulting cortisol surge in someone Miotch's age can cause freeze up.