I don't know if what I experience in changing visual style of journeys (across all psychedelics, not just mushrooms), maybe I would call them chapters. Sometimes I have many journeys that are hyper-real, other times they will be otherworldly, other times they will be abstract. I seem to have a series on a theme that then recedes and then a different style or theme will appear. Themes sometimes come back again, sometimes they are one-offs in my own experiences.
With DMT I find I meet entities that fit very much into the same concept over an extended time, which then don't reappear again, or if they do they come back some time later. For instance a while back every journey over several months I came into contact with beings that I would call place swappers (they play some kind of odd game of tag that involves them swapping their place in reality for yours) visually they displayed huge variation but conceptually they were pretty much the same. While these characters were in every journey I made for several months I haven't met them in maybe a couple of years now.