to "objective" something is to treat it like an object rather than as a person, in the scene you see that in many ways. One, o course, is the "human furniture" scenario where the sub takes the role of a foot stool or chair, or in a less extreme situation where they are reduced to animal or slave status and withing the scenario are considered less than human and are without rights or worth as people. As long as it's done with consent and for the mutual pleasure of everyone involved there's nothing wrong with it.