Before you introduce a client to multiple viewpoints she might not have considered the idea of being anything but a viewpoint in her body's head. And even if she has considered it, she might not be comfortable and familiar with anything else. One of our aims in transformational processing is to make her familiar with more, different viewpoints, including ones outside a body.
For example, in re-experiencing you might ask the client to experience an incident from a viewpoint 30 ft in the air. She might do that fine without anything remarkable occurring. But she might also realize to her astonishment that there really IS a viewpoint like that, and that she gets perceptions from there in a thoroughly different way than she is used to. She might also feel very light and clean while occupying that viewpoint.
The client might feel weird and spaced out after experiencing a viewpoint like that. She might also be somewhat unwilling to get back to her body perspective, in contact with the session room. She might enjoy the outside viewpoint so much that she would like to stay there for a while.
All that you really need to know about how to respond, is to avoid a scarcity of viewpoints and to increase the familiarity with different viewpoints. Never insinuate to a client that there is any scarcity of viewpoints. Don't ever imply that she really IS the viewpoint in her head, or that she really IS a viewpoint outside. Never imply that she can have only one viewpoint. Help her become comfortable having several or many viewpoints. Don't judge any of them as being more real or correct than others. But be sure that you bring her back to full presence in the session space before you end the session.
A person who has a fixed idea about being just one viewpoint might experience an internal struggle when she first experiences outside viewpoints. She might be split up as to whether she should be "there" or "here", and that might give her a headache and a condensation of mental energies. That is remedied by clearing up her beliefs on the matter and by making her familiar with having several viewpoints simultaneously.
Any time you get the client in contact with an unusual viewpoint, you might have to spend a little time getting her familiar with it. You can let her take some time and experience things from there, tell you what she perceives, move around a little bit, and so forth. Don't move her on to something else before she has digested the experience.
After dealing with viewpoints that are elsewhere, it is often necessary to re-familiarize the client with the session space. That will make her more present and grounded. You would have her look around in the room and point out some things, you would ask her questions about something in the present, or you would ask her what she is going to do next.
In transformational processing you bring the person into contact with many new perspectives. You work on increasing her flexibility and fluidity as regards to viewpoints. But you do this gradually, while always maintaining a grounding in the current physical reality. You show her the stars, but you make sure that her feet are solidly planted on the ground when you are done.