If Peas Could Talk

On the way to school this morning:

her: "Hey mom!"
me: "What's up, buttercup?"
her: "I'd like meatloaf for dinner, and cold carrot sticks - they HAVE to be cold!"
me: "Okay. I'd like to make peas too, for some reason I've been thinking about eating peas..."
her: "Okay." (pause) "You know if a square pea could talk, it would say it doesn't like candy."
me: "What?!"
her: "You know, square peas...they don't like candy."

I have no idea what she was referencing. We hadn't any time to reflect or for her to clarify as we arrived at the school drop off zone. She got off to school and I've been stumped all day.