Years ago, on the CBS show, Dave introduced a special event. It was boiling water. On the stage, there was only a transparent (pyrex) pot on a hotplate. There was thrilling music and many many different camera angles. The segment ended when the pot came to full boil: the transparent pot allowed the viewer to see the water all agitated. There was no other comment, no attempt to provide context, no other jokes.
It was an absolute triumph of form over content.
For me, this was an eye opener about the show as a whole. In an effort to be novel but without any real content to deliver, the Late Show could deliver a time waster, but it would ultimately be familiar and non controversial, yet still a little peculiar.
I’ve always remembered this odd bit, that lasted probably less than 2 minutes.