CIRCLE WITH A DOT

@swift @isisevrinen @marcioaleks
That's the question, and Archimedes has nothing to do with it.
When a fluid spins in a container like this (what the hand does is make the whole fluid spin), you get a secondary recirculation. It's called Bodewadt pumping, and it is related to Ekman pumping.
The recirculation dives nears the vertical walls, goes inward toward the bottom, and then flows up in the middle, exactly the behaviour of the fruit in the video.