Clever idea but if you're tech-savvy enough to shop this way using your smart phone and QR codes surely you're capable of doing all of this online?
People don't trust some things without being able to see them, and food is one of them. Being able to recognise that a particular item is the one you like makes them happier.
Once they've used it a couple of times they'll be re-ordering without bothering with the scanning, but to bring in first-time buyers, this is very smart.
If nothing else, they can browse a whole wall of them at once, seen at normal size, rather than having to click through lots of tiny pictures.