I added a conditioning stage because the gap between depositing stuff left on the platform and foraging for items seems too large without an intermediate step. Now I put a few things on the platform and the rest on the mounting stand and in a cup mounted a few centimeters from the platform. I think this will require a gradually moving them farther away from the vending machine until they will pick them up from the floor of the balcony.

They are now pretty good at depositing caps and butts left for them to use.

https://cdn.hackaday.io/files/1847547904515136/VMFB-MC_15-38-18.mp4

And have started to understand that they can bring things that are not on the platform.

Jackdaw sinking a cap taken from the cup near the platform and getting robbed by his friend.

https://cdn.hackaday.io/files/1847547904515136/VMFB-MC_08-27-44.mp4

Jackdaw taking a bottlecap from the stand behind the vending machine and sinking it.

https://cdn.hackaday.io/files/1847547904515136/VMFB-MC_09-18-18.mp4

Jackdaw taking a cigarette butt from the cup near the platform and sinking it.

https://cdn.hackaday.io/files/1847547904515136/VMFB-MC_17-03-10.mp4

This seems like good progress for one week. As soon as they get good at it, I'll move it farther away. I can swivel the bowl arm to make the bowl about half a meter away from the platform. I also need to start lowering it closer to the ground.