> you just drop everything you picked up into the box, it scans all the RFID tags and makes sure the weight is correct, and it's all done.

Well, not exactly. I saved a bundle of money inadvertently in a Decathlon in São Paulo. I read the instructions, but didn't understand the Portuguese completely. I dumped a ton of purchases into the bin, watched the screen scroll through the items, and paid the bill. When I got home I realized that I'd only been billed for about half the items. Next time I was there, I read the instructions more carefully and discovered that they said to put the items in the bin one by one