Tecnically, the show is a vignette. Vignette's usually have a basis, but no plot. Other Vignettee's include The Me Nobody Knows and Runaways.
"Do you know what pledge time is, Andrew"? said the PBS Executive.
"Yes", Lloyd Webber replied. "My 50th birthday special must be one program that gets done a lot."
"No", mused the man from PBS heedlessy. "Not so much. Our Stephen Sondheim Carnegie Hall concert. That's a big one."
Spoons, forks and knives seemed suddenly to suspend their motion in horror, all around the table.
More technically, it's a series of vignettes with a common theme. Vignettes themselves are merely short descriptive scenes. They could include mini-plots (i.e. character with an objective or action within the course of the scene) but they do not have a complete beginning, middle and end.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian