Still don't know where the customers are. How do you fill the orders?
If you have completed an order you move up to the very last room. The customer is sitting there. Then you bring the food to the mouth of the customer.
Ah... mouth of the customer. I couldn't figure out what it was. How do you stuff it into the mouth of the customer?
It is indeed a little bit of a weird mechanic but. the customer is basically sort of a baby. You have to face the customer while holding the food and then it will disappear, and you will be rewarded with a coin.