Kind of reminds me of the McDonalds I used to work at. As others have stated it seems to clearly work, but perhaps they were off their game, that particular place is not used to it, or might have had a lot of newer people there.
I say it reminds me of McDonalds, because while the McDonalds app had been out for at least six months, or even more so, it was always awkward when the rare occasion someone would mark themselves as there at one of the number spots outside and there order would pop up. The order would be made, but then it was the question of who knew where it would go. As people can either be inside, or outside in a number spot. Due to lack of training, switching of roles, and the rarity of it all, even managers would grab the order and take a minute to remember, or realize where the order had to go. There seemed to be only a few of us who remembered and it seemed that unless you were there (at the time of initial training), you wouldn't know what certain symbols/colors/numbers meant to let you know where the order had to go.