The tool being used is called a stamp or a roller
I'm not extremely sure about the context of this, but I would totally draw a bunch of those fluffy worm things, or maybe a kitten- I have a cutesy mindset for this project. Try and draw a small animal perhaps!
The flashback is the film term for the interruption of chronological plot time with a shot or series of shots that show an event that has happened earlier in the story.
<u>Explanation:</u>
Histoire d’un crime directed by Ferdinand Zecca scened the first flashback scene in cinema in 1901. Flashback also known as analepsis is narrative device that shows something happened in a past time or past events classically in accordance to the present time of the narration.
It interrupts the main sequence flow and takes the audience to a window of different time. Sometimes it lasts for few seconds, sometimes it can be the maximum part of the movie, it generally depends on the plot of the cinema.