A brasserie has to hold together a wide menu, with its starters, mains, set menus, desserts and the day's blackboard, and a service that moves fast, especially at lunch. The waiter only has time to come by once for the order and once for the bill.
The daily special is the everyday headache. It changes each morning, and in a large room the blackboard cannot be read from the back or from the terrace, so each waiter announces it at every one of their tables. Over fifty covers at lunch, that is a lot of time spent repeating the same thing.
The bill is the other moment when things get stuck. At the end of service, a guest in a hurry who waits five minutes for the bill to arrive is a table that is not turning, and a guest who will be less keen to come back.