It's Pipis not Pippie's
And not Pippy's either!
The pipi is a shellfish found on the surf beaches of fraser island.
It has a solid white, elongated symmetrical shell with the apex at the middle. So they're bivalves, meaning that they have two shells, joined by a hinge.
Under one roofline but with no common wall, total privacy and space Pipis at Poyungan imitates its namesake by adjoining similarly as a bivalve.Photo courtesy of Qld Museum