I haven't done one of these in a long time (more than 5 years ago). But it usually was related to a place that served Coca-Cola products. If this is the same company (based out of North Carolina), they also do a large chain of amusements parks as well during the summertime.
Basically you go up and order. If they UPSELL you and say the right things, there is a form to "award" them and you have to get the manager to sign it off. You leave the prize (sometimes gift cards).
It's basically on "on the spot reward" for a job well done. If they fail, there is a different form and you fill that out and manager signs that one and you ship back the prizes.
In today's word, I don't know why they just don't give a DIGITAL gift card and skip the shipping thru FedEX. It just costs more for the project, but maybe a PHYSICAL gift is more meaningful instead of telling the employee to check their email for a digital gift card.
I remember doing it at a burger place and the lady was so happy, she wanted to give me a hug.