She may be doing it for another reason, I was just stating when I see it with my ducks. My train of thought was that if she is in pain that may be why she is not wanting to get into the pool and why she is moving her wings to cool off. Have you checked her feet for bumble foot? Or for any injuries?
I agree not broody from the video. However, my ducks do this in hot weather when they are trying to cool themselves down. I turn the fan on, they all waddle on over, lay down and stop.