The smears.
Added 2017-11-01 20:25:43 +0000 UTCYou may saw this when you stop an onlgoing animation, we call this effect a smear.
There is an example with two type of this effect:
The straigh line, it gives a smoother effect for the transition, also is mostly used for many parts moving at the same time (like parts of the body, parts of a background), create a speed effect that also works fine if the element you want to animate moving is at full speed.
The separated line, gives more element and graphic to the transition, also easier to notice and more illustrative, generally used for a particular part like the eyes or an element on a whole composition. You generally need less frames with this effect than the straigh lines but for the example I used the same rate :)
