In fast food, people choose standing up, in a queue, reading a board placed behind the person taking the order. The guest at the back cannot read a thing, the one at the front is hurried along by those waiting, and orders what they know.
Yet few orders have as many parts, the meat, the bread, the salad, the sauce, meal deal or not, the drink. Each question takes a few seconds at the counter, and at lunch that is repeated for every guest in the queue.
A good share of sales is also takeaway, ordered by phone at the worst moment of service. And every call means one person who is no longer serving.