Both of my cockerels (about 18 weeks old) do this same thing. -and, my dominant cockerel will also "dance" at the other cockerel as a show of dominance/territory, etc. I've observed it as a "keep your distance" thing when it is directed at the other cockerel. (Initially, the two sparred a good bit when they were very young. They no longer do this, and have established the "flock leader".) Other than the wing down and leg shake, the cockerels get along just fine. -and, it is always the dominant one that exhibits this behavior. My other little guy just dances for the gals. He gives my alpha his space.