Headcanon time!



When Celestia took Twilight on as a student, Twilight... well, pretty much worshiped the ground she stood on. So, to hopefully get her little student to see her as another pony instead of some perfect untouchable entity, Celestia tossed aside table manners and acted like a slob in front of Twilight so the filly would realize that she was a fallible, ordinary pony (with godlike magical power and political control over the nation).



Instead, Twilight took to shoving food in her facehole in mimicry of her princess.