샤라락 is not a real word.

But it can be used as a mimetic word which expresses an action or status when a thing moves/goes/changes quite quickly.

For instance,

꽃잎이 샤라락 떨어졌다. (A petal fell down slowly)

And in this context,

I think it is used to express feelings of love or shyness something like that.

Oh sorry Lol

Uhm Let's say this then.

샤라락 could be used when you want to talk about movement of some light things such as thin curtain, petal, a piece of paper, etc.

I think the speed doesn't really matter.

Thank you Layla for the response! (Sorry it took a while to reply though ^^;;;)

I am slightly confused though - you said it refers to something changing "quickly", but then the example uses "slowly". Also, if one draws out the word like "샤라라락", they're basically just drawing out the sound, right? Like, "swooooosh"?

I just want to be sure I have the general idea down since a Korean IG I follow (dahee.bab2) has been using it a lot lately (always followed by a tornado and a shooting star emoji). It seems to have become her favorite word haha ^^