BECAUSE SHE CLAIMS SHE DIDN'T GET A RECEIPT THE DAY BEFORE! That's what's so funny. Why do you need a receipt for donuts, and who cares if you don't get one?
A lot of fast food places have signs that say "If you don't get a receipt your order is free just call 800...." they do that to ensure that employees are ringing up orders on the cash register and not just pocketing the money.
Not sure why she thought it was such a huge deal that she needed to record it for "evidence".
It is amazing how out of touch people can be. Here she thought the video would cause problems for the employee and she ends up looking like a complete and utter bitch and is now faced with the scorn of the entire Internet.