Continuity mistake: When Morgan emerges from the kitchen after Topanga picked her up from school, a wall is visible behind the door leading to the kitchen, even though the kitchen itself should be visible. (00:02:18)
Continuity mistake: Just after Cory talks about being a "baby shower machine", Morgan walks past him. There's then a quick shot of Alan and then we see Cory again, and again Morgan walks past him. It's not the same shot from two different angles, as Cory is acting differently each time.
Chosen answer: In the present day, with the United States abiding by more stricter school health laws, for the most part this wouldn't be in school cafeterias as many cannot even have carbonated beverage machines now. However, in the 90s when the show takes place, it wasn't unheard of for there to be coffee machines in the cafeteria of small schools where the teachers eat with the students as we see them do often in the show. The idea being that the cafeteria was small enough so a teacher or hall monitor could catch a student before they could drink the coffee.