How to achieve this motion with line drawing?

Hi, Please can anybody be kind enough to share any tutorial on how to achieve movement of certain objects in hand drawing for kids. I saw this video where the person draws a shark and when his hand is drawing something else on the shark, the shark tail moves around a point. The drawing is just line drawing and when the person hand comes near the moving or rotating object, its stops as if showing the original drawn tail that time. I understand editing in filmora but i think it may related to adobe after effects. Need someone’s help to a proper tutorial. Would be really grateful.