I'll show the progress in reverse here. Start at the bottom of the post if you'd like to see it from the beginning.
I was noodling around with the dark purple and noticed the shape sort of resembled a shark.
I added two similar shapes in the larger circle and will add a third toward the center of that circle.
Very thin beige and light neutral-grey are added in layers over the background area and in the larger circle so the eye is drawn to the smaller circle at the top left.
Scales patterns in turquoise and purple are added using a stencil I made. I wanted to add texture to the background area as well as accentuate the circular motion and to indicate that the circles are moving in opposite directions.
Sharks. Powerful, focused, curious creatures. Superior instinct and a remarkable drive for survival. Actively moving forward through life. Silent before they attack.