Shopping, now with less buying anything
While it seems somewhat silly in the form of a grocery store with no products, just photos of items and QR codes, the Tesco example in this article from Ubergizmo does make a lot of sense:
Yihaodian has already done something similar on a smaller scale by sticking up posters in subway and bus stations, while in South Korea, Tesco has launched something similar where customers can shop for groceries at the subway while waiting for their trains.