Decomposing images into a bazillion dancing particles certainly isn’t a new idea, but this three.js based demo from @BlurSpline is a particularly (heh) nice example.
Spherical repulsion and noise are among the transition effects available, and while the reformation of each subsequent image could be a bit smoother, the overall effect is still rather pleasing.
The majority of the heavy lifting is in the shaders, which are fairly readable in the source – worth a look, as always! 