The asymmetry of the Adowa dance movement might arise from the asymetry of the clothes. The Kente is worn in an asymetric fashion, similarly to a toga, and must be prevented from gliding down the shoulder. This restricts the movement in some way and favours the asymmetry superposing the underlying alternating but otherwise symmetrical, walk-like movement. This assymetry is then worked into different variations of movement.
Somehow this asymmetry contributes to the way this movement feels beautiful. If you know how to dance it, it is also beautiful to watch, but first and foremost it feels beautiful.
(Again I think one should study African dance by motion capture techniques. When I first had this idea in the early 1980s, it was prohibitively expensive, but now such systems might be afordable. To be checked out.)