Going back a few years I was not a very verbal Dom. I tended to focus upon bondage and power exchange was always part of it but it was not the primary focus. Today I am not very verbal during a scene except when I am verbally humiliating a sub. Most communication is non-verbal and a Dom can communicate volumes in a scene to an sub with unrestricted vision.
Participants in a scene need to be in the proper headspace to ensure the verbal dialogue, or monologue, does not erode the integrity of the scene. I am sure all of us have watched some sort of BDSM video where it is obvious the Dom and sub are performing a script as opposed to building a scene based upon their mutual interests. That being said, the goals of actors in a BDSM porn are very different than a typical Dom or sub in a scene.
The picture below of 157 and me is one that captured a moment while I was letting him know a few rules during a scene.