It seems like all the stories are intertwining by the end of "The Pie," but really, they stay completely separate, linked instead by a common trope: in Jerry and George's case, their furious shaking of the head when being offered food, and in Kramer and Elaine's case, their fascination with the mannequin. So while, plot-wise, it's not quite as masterful as Seinfeld's best, it's still a hell of lot of fun, particularly if you like jokes about Jerry's obsession with cleanliness like I do.
Like a lot of Seinfeld episodes, "The Pie" never answers the central mystery of why Jerry's girlfriend of the week Audrey won't eat the apple pie at Monk's. She likes pie, she wasn't full, and she even walks around with donuts in her purse. So why does she just flatly refuse to take the pie? Apparently this was inspired by something that actually happened to Jerry and got him really mad, and he's almost quietly intense in that first scene. I kept willing Audrey to just eat the pie, because Jerry's obviously just so freaked out that she isn't. Instead of inventing a convoluted reason why Audrey doesn't eat the pie, Seinfeld looks at why Jerry or George might refuse food, which I think is the right move, because those are the characters they and we know much better, and Audrey's reasons would be rooted more in circumstance and would be a lot less funny.
For Jerry, it's obviously his general germophobia. Now, that's not to say most of us wouldn't be grossed out at the sight of the chef at a restaurant exiting a bathroom stall and not washing his hands as he goes to prepare food. But honestly? I bet in that situation I would have just rationalized it somehow: Maybe he washes his hands in the kitchen! Maybe the pizza getting cooked makes the whole thing pointless, right? But Jerry, on a date with Audrey to her father's restaurant, is never going to be anything but horrified by the sight of chef Poppie kneading pizza dough with his unwashed hands. As he tells George later, "At least pretend, for my benefit; turn the water on; do something!" "Yeah, like I do," George says, prompting an even more pained look from Jerry that is just utterly priceless.
So, in George's case, why does he reject the food, on a job interview where he's been told to be a 'team player,' no less? Well, the immediate answer is that the food has been poisoned or sabotaged in some way, but the real answer is because George is an awful guy who can't just be happy with a little victory. The B-plot of George trying to get a suit for half off in a secret sale is fun, and watching him revel in victory, newspaper in hand, is always good. But like George gloating over getting Time magazine before the serial killer in "The Airport," we know a comeuppance is coming, and that it'll be juicy. It's almost harder to watch George refuse the cake than it would be to watch him eat it and throw up or what have you. I got close to saying, "Christ, just eat the cake already!" and Seinfeld rarely provokes that kind of a reaction from me.
Elaine's creepy mannequin is the perfect kind of Seinfeld B-plot, in that while the A-plot concentrates on such a minute detail of manners, the B-plot is self-consciously wacky, with the imperious store clerk, the bizarre tableau of the mannequin being spanked by another, Kramer's sexual use of the mannequin to break up with his long-nailed fling, and finally, the revelation that Sam Lloyd from "The Cigar Store Indian" created the doll in Elaine's image. The whole thing is just the right amount of madcap, and yet it's integrated very well with the other plot so it doesn't feel like we're just jumping, jarringly, from world to world.
Oh and Kramer's C-plot of his back itching is a nice marriage of the two concepts. On the one hand, it's got to be the most mundane plot idea ever: Kramer has a scratchy pillow with no case at home, and it makes his back itch. On the other hand, with Michael Richards delivering these lines and jerking around spastically at the Monk's hostess scratching him with her long nails, the whole thing is even zanier than Elaine stealing a mannequin that looks like her from a clothing store. At the end, when he fondles Elaine's mannequin to scare off the Monk's hostess, you feel like the writers just needed a punchline to close the episode, and that sight gag made the most sense, even though the scenario makes so little sense. But Richards, unsurprisingly, makes that work.