I wondered when they stopped actually using the grill. I worked in a McD's down Silver Spring way in 1974 (the paperhat era), and the folks that worked the grill were the top of the "food chain" so to speak. I never got to the point of being able to work grill during the lunch rush, but you're right... the appearance of the food was important. We tried to make what we called "Movie Macs" or burgers that looked as good as the ones on the commercials.
Cleanliness was more important too...we usually had a person dedicated to cleaning the "lobby" at all times. We would have contests to see who could sweep, mop, clean all tables, and empty the trashcans the fastest.
Sadly, I can guarantee you that those days are gone forever.