I know this is an old post but i read a few weeks back cause my 6 month old boy is doing the same thing he's a barred rock and about 7 lbs right now and i have kids running around all the time and want to keep him for my girls for meat production.
Well i have neighbors that have chickens also and they come around, well i've noticed that he makes sure they keep there distance from his yard he makes sure that those hens see him and when they do they flap there wings and he flaps his and they all go there own way. him keeping 1 eye on them. so that got me to thinking about it. so i tried something i walked toward him and he flapped them more and more i walk away he doesnt flap then i turn and face him he flaps. so im thinking its a good chance it might be a sign of respect towards the more dominant person /chicken. same way the hen is doing it to a rooster not of her flock and him doing it to me. hes never charged me stood up to me or anything.