I have no idea what to call this effect, it reminded me of how iron filings reacts to a magnet so I am calling it that. If you are looking to add some epic level image effect then you can’t go wrong with this image transition effect from Szenia Zadvornykh. You can see an image that disintegrates into microparticles and then it reforms into the next image.
Want something similar for text try out this snippet.
If you are having trouble with the pen, try the archived copy on GitHub