That's a nice bin-picking system. Bin-picking is a classic robotic manipulation problem [1], and they're doing a good job. They target the object and approach it from an angle where pickup is possible. The unusual thing here is the range of objects picked. Most bin-picking has a far narrower range.
It's a vacuum picker, which is limited; they couldn't pick up a perforated metal pencil holder. But over 90% of the items tested were vacuum-pickable. That's probably a reasonable figure for Amazon's inventory, since books are vacuum-pickable. Amazon can sort their inventory into machine-pickable and non-machine pickable.
The new system is really slow, but that can be fixed.