Water transfer printing on a car wing mirror

Online you can find materials to paint anything like in the gif. It's a little bit expensive but it's worth it

The small, cheap version is some drops of colourful nailpolish into water, make some patterns with a toothpick and then dunk shit in (eg white phone case)

You can do it with spraypaint on water too, Here's a link: https://www.youtube.com/watch?v=EuENnvz54ig

Water marbling witches