the Mass is a sacrifice, NOT a meal.
the priest stands in persona christi, the head of the mystical body.
the sanctuary is the head, the nave is the body.
the head and the body are united when they both focus on the same thing, Jesus who will return from the East.
the hymn does not go "People look East except the priest..."
The VII pizza-hut churches have the head looking away from our Lord and gazing at its navel.