It makes sense. Flan chomped on the menu, breaking the 4th wall's effect on the menu thus releasing the menu from it's intangible state which allowed it to be chucked.
Whooooa...A Monster AppearedOh, so it's somewhat like a game, huh.EncounterEven in battle, we don't have any equipment, either...Command?Enemy Defeated!Wait! Flan! Stop nomming on that!F-Flan?