Customers, who need to have the Amazon Go smartphone app installed, swipe a code on their device on the way in. At that point, Amazon’s system of cameras and sensors tracks them through the aisles, charging a credit card for items they take after they leave.
That system, which relies on hundreds of cameras mounted in the ceiling, as well as human employees who check in when prompted by the system, is essentially unchanged in the new facility, Amazon says.
See the full story here: https://www.seattletimes.com/business/amazon/amazon-has-a-second-go-at-cashierless-convenience-store-in-downtown-seattle/