First an example of a reservation by a customer. The customer has already chosen for which performance and for how many people the reservation should be. The venue choice is automatically left out here, because there is only one venue available. The date and time choices are also omitted (but still shown) because only one choice is possible. The maximum number of tickets that can be purchased simultaneously is set to four, so it is correct that this customer can buy two tickets.
You can visit the fake advertisement on the upper right to see for yourself.