I see classic Brownian motion, fluid flow, and colloids combining. Nothing saying nanobots. Just because somebody has an MD doesn’t mean they recognise Brownian motion in a microscope slide. Botanist Brown observed it in pollen grains in 1827 and initially thought in was evidence of vitality (living and swimming of the pollen grains) just like this lady. Then he tried it with 100 year old pollen grains and they “swam” just like the fresh ones did, then he showed it with particles of granite, etc so it did not require an active nanobot or pollen grain.
Maxwell, Boltzmann, and Clausius thought correctly that it was a thermal phenomenon and worked on it circa 1860-1880. Einstein explained it quantitatively in 1905.
https://youtu.be/ernnQJwaKTs?si=Vao_WgMTjfjMOc9n
https://www.ge.infn.it/~zanghi/FS/BrownTEXT.pdf