The episode: “Operation Double 007,” ep. 508
The riff: Chided by Joel as a man in a flowing golden robe walks into the scene. He is quite bedazzled.
The explanation: My, this is one dense riff. First, a “kaftan” is a type of front-buttoned overcoat or overdress of many Islamic cultures. It came into the vogue among American hippies in the 1960s and 1970s. Jessye Norman, on the other hand, is a Grammy-winning contemporary opera singer associated with a lot of classical Wagnerian operas. I believe the reference refers to the sort of costumes she typically would end up wearing in these shows.
Novelty factor: This is one obscure riff, even for MST3k. Why do they even know this?