While I’d had a passing familiarity with the stylize parameter, which formulates whether to display an image closer to the prompt, but less artistic (low value), or more artistic, but less accurate in detail (high value), I had not known you could string several permutations together in a sequence.
MidJourney prompt: watercolor illustration, side profile, woodpecker, autumn, sad –s {100,300,500,700}
This does explain why my red-bellied woodpecker goes from its traditional black and white speckled wingspan to a pattern that feels a little bit more like the coloring of a nuthatch. Plus, at –stylize 700, MidJourney took the stance that if humans are going to call it red-bellied, its coloring should better align with its name.