That's a hen, and a darn beautiful one at that! The neck feathers give her sex away. Strutting is done by males and females. My flock started mating two days ago and the females started extreme struttingg just like the males with tails fully up and fanned as well as wings in the down dragging position.
That is a hen in a submissive breeding posture, not a strutt, thought they do that too.
Males are covered with black lacing, hens just have it in the areas that your girl does.