I assume you're referring to the gif version.
The technical answer is that it's an artefact from the process of scaling down, colour indexing, and the way the frames are split by difference and then summed back together in playback. It is not present in the hyper HD webp version.
But of course every aspect of the technical process is governed in part by artistic awareness, I choose to interpret the seemingly random noise as artefacts of the painful awareness of the void inhabiting the soul of humanity, having believed ourselves to be masters of everything, by interaction with the diverse technological nuances of human creation we reveal our failure to reproduce feelings with their seemingly infinite nuances, and our ultimate failure to gain mastery over ourselves.
( ,
Sat 3 Sep 2022, 16:08,
archived)
But of course every aspect of the technical process is governed in part by artistic awareness, I choose to interpret the seemingly random noise as artefacts of the painful awareness of the void inhabiting the soul of humanity, having believed ourselves to be masters of everything, by interaction with the diverse technological nuances of human creation we reveal our failure to reproduce feelings with their seemingly infinite nuances, and our ultimate failure to gain mastery over ourselves.