As the Geeks go to leave the Iron Horse, Maureen approaches and puts her finger on the blackboard and starts to rub out part of one of the menu items. But in fact on close inspection there is actually already no letter where she starts rubbing, as when she puts her finger onto the blackboard it already says "Pan Fried ass", so she doesn't actually rub any letter out. As Maureen leaves, she points at the blackboard, which still says "Pan Fried ass". After she has left the Geeks immediately go up to the blackboard, which now says "Pan Fried Butt". Presumably the joke had originally been to have a menu entry of "Pan Fried Bass" get altered by rubbing out the "B", but the resulting word must have been considered too offensive and been changed to "Butt". In either case, Maureen never goes anywhere near the blackboard with chalk in time to change it.