We see lots of images of stern Dominatrixes weiding whips to control their minions, the internet is full of adverts for Mistresses who will shout and scream abuse to gain control. To me control is much simpler than that, control is a state of mind. It is the state of mind of both persons concerned and it is beautiful. I found this pic on Spit is Me on tumblr and I think it says it all.
There is no shouting or screaming, no whips or chains and yet she is clearly in control, he is her plaything her toy