"Submissive" is a misleading term. A submissive doesn't so much submit as surrender. The difference is that surrender suggests complete giving of one's self over to the experience. Submit, on the other hand, suggests mere acceptance, endurance or toleration of what occurs; i.e., without opening up and accepting the experience.
Commonly, a submissive has already surrendered their authority over a range of activities to their dominant partner, and part of their experience of power from their partner is knowing that their partner can simply take them and do any of these activities with them at any time without seeking permission or agreement.
Note that a submissive can withdraw their permission (i.e., reclaim the authority) at any time.