One of the tasks of potty training is association. By reminding Olivia that everyone uses the potty, the hope is she's more likely to use it herself.

Yesterday, while getting dressed for a zoo outing during Daddy Day:

Me: "Olivia, where does daddy do poo-poo?"

Olivia, in a bright, cheerful tone: "On the potty!"

Me: "Where does mommy do poo-poo?"

Olivia, slightly muffled by the shirt she's pulling over her head, "On the potty!"

Me: "Where do the cats do poo-poo?"

Olivia, with a suddenly serious face: "On the floor."

Well, yes, there is that...