This would allow picky customers like me to order up their favorite drink with all the extras simply by sliding a card. The main purpose here is so impatient people don’t have to speak out their drink order only to have the barista screw it up. It also helps cut down on those times where the barista asks you to repeat your order a million times.
Another thing to keep in mind is how many Starbucks locations have incomplete menus. The kiosk would allow all Starbucks locations to have an easily updated list of drink options for people to look through. Customers would also have a better idea of how creative they can get with their drinks, which could possibly get annoying to the baristas.
(Picture is of IBM AnyPlace POS)