Those new to power exchange would be forgiven for thinking the Domme is in charge. If we exclude everything that's not safe, sane and consensual, we're left with something really rather beautiful. - Communication on an entirely new level. This is empathy.
At the start of the process there is the negociation. The establishment of soft and hard limits. (Soft limit? These are: I don't really like this, but if you do, I'll do it. But not too much, please. Hard limit? I really don't like this. You do this, I'm not playing with you, ever again.) You can see very quickly that the submissive is laying down the groundwork. Also, the safe-word is used by the submissive, not the Domme. Again, it's the sub that can instantly stop play. For things to remain safe, sane & consensual, this is how it must be.
When a couple have been playing for a while, and they know eachother very well, play can get a little more experimental. Soft limits can get pushed; gently ! Encouraging the sub to do things could all be part of the play.