This is River again spinning during the same 'burn' when "Wheel of Fire" was shot. This move is called the 3 beat, which refers to how many rotations each poi does before once complete 'cycle' is complete.
With these shots, what did you do for the flash. I imagine it is off camera. Did you us ttl or did you set it to manual. If ttl did you just let it do its thing or did you do some flash compensation. If it is manual what power did you set it at? I don't know why it took me this long to ask, but it just came to mind:P.
Just remember, "If you play with fire, you may get Burnt".
BE CAREFUL !
E J