There are times when it's acceptable to deny a tip to a server. Receiving bad service would be a good reason, but so would being outright insulted by the restaurant you've come to eat in. Based on what's written at the top of this bill, we're seeing the latter in action here.
Given this business makes its money by selling food to people who are hungry, it should probably avoid body-shaming the people who come to eat in it, else it may find that they stop turning up.