What would be the problem with a bowl of liquid?

The balancing there comes from the wrist joint, not the fingers. Obviously this device is supposed to be mounted on a wrist joint that can rotate (pitch+yaw). Wrist joints are pretty well-understood these days.

Rounded handle I don't see the problem unless the hole is too small for one of the fingers.

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varjag 7 hours ago | parent [-]

Holding a rounded handle with a rectangular profile slider is inherently unstable as it's extremely sensitive to the pinch point.

And the bowl has a radius that make orthogonal grip impractical.

	▲	octoberfranklin an hour ago \| parent [-]
		But it has two pinch points. There are two separate grippers. Look at how it uses scissors. If the radius of the bowl is that big it's too big for anything one-handed (with a reasonable size hand). So use two hands, like people do.