Your customer is using shelf to better manager their ordering. A customer of yours sent you an order through shelf. You have the option to accept or reject the order.
When you accept an order, your customer will receive an email back stating that you have accepted the order. Your customer will expect to receive the order on the specified day/time.
When you reject an order, your customer will get an email right away. You will have a slot to enter why you are rejecting the order.