That pic depicts a pretty young girl. If she was an intern or on a probationary period...he’s abusing his power as her boss.
I have been of the opinion for a very long time now that Mr Letterman is the King of Creeps. He’s smug, vain, more racist and sexist than he lets on, and not more than a little hateful. His presentation has a bad, somewhat unidentifiable flavor to it, like cottage cheese that has been left out on the counter a bit too long.
Good old Dave never misses an opportunity to take a cheap shot at someone, anyone—even people in his audience who are his fans are fair game for his snide, derogatory “humor”.
So with that in mind: Let the games begin. ;)