“Waiting for the Artist” presents an overview of the long and storied career of the acclaimed Izabella Barta, featuring such memorable works as “Coat Rack,” “Late for Dinner” and “Ein Tag, Ein Frankfurter.”

Except the artist, and her work, isn’t real. Neither is the documentary—it is an episode in the third season of “Documentary Now,” premiering Wednesday on IFC. The television series is produced by “Saturday Night Live” alumni Fred Armisen, Bill Hader and Seth Meyers, with a cast that includes Michael Keaton, Natasha Lyonne...