[jaxomlotus]

I'm betting that by the time this is real (and assuming the shown implementation is what actually goes live), everyone will have their own personal QR code so there will be no mistakes.

[toyg]

Take a pic of your neighbour's QR, print a copy, profit.

[shpx]

Wait 40 minutes, don't get package, email support, they review footage/delivery data, see drone going to your neighbor, press charges for petty theft.

[varelse]

Did I say anything about keeping or even opening the packages? If the drone is using some sort of convnet or HOG to detect the landing pad, I can only imagine hilarity would ensue if its visual field were saturated with multiple copies of the target image, a sort of visual DDoS if you will...