Continuity mistake: In the open, Max and Earl are standing at the end of the counter and when Max holds up the cup, Earl covers his face with his hand. The shot changes and Max is still holding the cup in the air but both of Earl's hands are now on the counter.
And Not-So-Sweet Charity - S2-E18
Continuity mistake: In this episode, Chef Nicolas visits the diner and greets Max as if they know each other, and even teases her about giving her a low grade for her flan. But this is just season 2, and Max doesn't go to pastry school until season 3. (03:05:00)
Suggested correction: This does not happen in the episode mentioned in this post. They joke about her low-grade flan in season 3, episode 18 - time stamp 03:03.