What kind of emotion do subs like to see from their Doms during play?

Looking at a lot of BDSM videos and pics, it always seems to me that the Dom is not very into it emotionally. Maybe it's because they're working in front of a camera, but they always seem very cold and distant to me, and I was wondering whether that in itself is a turn-on to a sub.

Personally, I tend to be very passionate when I play, and very emotional. Having a woman under my control arouses the hell out of me and it shows, and I've been told that seeing the desire and lust in my eyes is a terrific turn-on. I have a hard time imagining being as emotionally distant during a session as these Masters I see in videos.

---dr.M.