I paid by cash, but she did not know I was paying cash when she explained how they do it! She said something like, "Here is your bill. you need to pay the whole amount, and after that is taken care of, I will give you your $40 deposit in cash." I thought it was strange, but I followed the directions. I thought why not just write up the bill like normal, and at the end show the deposit and deduct it from the total owed.
Maybe it is so people tip on the whole amount and not just the amount owed after the deposit is subtracted??? I bet that is it! I would hope most people know to tip on the whole amount of a bill and not the adjusted amount after ANY discount. But I suspect, folks who work there were concerned about this, and this was their best solution!