Bumble (Metaphor)
This metaphor is a mistake made on Grandma's part. She misidentifies the baby that arrived in Mommy and Daddy's lives 20 years earlier, calling it a "bumble of joy" rather than a bundle. For the rest of the play, this baby is referred to as a "bumble." This highlights the fact that Grandma is older and mixes up words, as well as the fact that the baby that was adopted was always defective or wrong in some way. The baby becomes less than human, not a baby at all, but simply a "bumble."
Van men (Metaphor)
In order to keep Grandma in her place, Mommy and Daddy devise a kind of threat: the van people. While never explicitly defined, the "van men" or "van people" are always nearby, ready to take Grandma away. The men thus become a metaphor for Grandma's exit from the apartment, representing a force that will separate the elderly woman from her family.
Mommy's Head is Like a Banana (Simile)
At one point, Grandma takes Mrs. Barker aside and tells her stories all about when Mommy was born. She mentions that Mommy's head was shaped "like a banana" at birth, which made her a very difficult delivery. It's an odd simile—could a head really be that long and thin and curved?—and Grandma's use of it emphasizes how difficult Mommy was, and also perhaps implies that Mommy is crazy ("bananas" in the head.)
"You're like an old house" (Simile)
When Mommy tells Mrs. Barker that Daddy has always wanted to be a senator, but now has decided to become a Governor, Mrs. Barker tells him he is "like an old house," which Mommy interprets as a compliment. While it is not exactly clear what Mrs. Barker means, she uses this simile to suggest that Daddy is solid and settled.
