I think at this point, SE should just let people who ordered the food from Grubhub use their order receipt for proof, and send out the emote code. It has all the necessary information on it: Order date and time, order amount in dollars. Just like what they did during the Butterfinger promo campaign. It has been done before and worked, so there is no excuse to not do it. Unless some lazy ass management doesn't care about the bad PR.