Comment by fenomas

I see what you're getting at, but I think you're focusing on the incidental. An animation is good if it's clear and intuitive in motion. It may often be the case that good animations also look nice in a screenshot halfway through, but (a) they don't always, and (b) working well in motion is obviously the more important of the two goals.

As such it makes no sense to worry about the latter thing - it's not a signal whether the animation is good or not.