When I say “show within a show” here, of course, I don’t mean a fictional TV show, like TGS or Itchy and Scratchy. I mean the particular phenomenon of a subplot or story thread that, for whatever reason, is significant and yet separate enough from the main story—either in tone or plot—that you feel like you’re watching a tiny TV show that someone decided to hide in a larger TV show. […]
One of the advantages of the show-within-a-show is that it enables you to treat subjects that, in themselves, would probably not survive a network pitch meeting. Though big-network audiences will follow dramas about, say, sharky defense firms, building a primetime show about crisis communications management is probably a stretch too far, and maybe better suited to cable. But The Good Wife, in its moral and narrative sophistication, is about the closest thing a broadcast network has to a cable drama—just enough to sublease some of its dramatic office space to the spinoff-within-a-show that I like to think of as “Eli Gold: PR!.”
When done right, the show-within-a-show technique is richly rewarding, when done wrong, well, it almost feels like a distraction.