When Sayuri saying "pizza", somehow i start imagining Banana Joe in "the amazing world of Gumball" humming "pizza pizza pizza" and now the song get stuck in my head again...
What is the pizza joke a about? To my knowledge "pizza" is piza in japanese and head is atama. is it supposed to be some sort of pun?
The Japanese joke you're misleading someone to incorrectly answer hiza (knee) while pointing to their hiji (elbow) except that Yurika didn't actually do the joke so who knows what's going on in her head. So hypothetically in English who knows what joke or trick she could've been going for and it ends in confusion all the same.