It does look like Biden had a bruise (blood thinners?) on his lower, left jaw (if the photos are unaltered). At Biden's age, people starting falling down (loss of balance, confusion, muscle control/strength issues?) like bowling pins.
Biden did what was in the best interest of the Dem Party and his own health.
I wonder if Joe is not well enough to fly (blood clots?) as much as he has been in the last few months.