I don't know if I'm missing the joke, but why do we assume the 2D stork people have a digestive tract and not a series of manipulatable pores that facilitate th

I don't know if I'm missing the joke, but why do we assume the 2D stork people have a digestive tract and not a series of manipulatable pores that facilitate the movement of particles in and out of the body or maybe similar to how an amoeba uses phagocytosis.