It's not just pizzas. For those that didn't notice apples also makes the list. It's a constant fixture in the film industry representing the same motif as pizza. These HRC emails were scrubbed before they were released. That the main reason we don't see moar evidence contained within them. JA just missed a few is all.

https://wikileaks.org/clinton-emails/emailid/27278

https://wikileaks.org/clinton-emails/emailid/15869