Some of these controls are more important to an individual than others, and different positions will have different effects. If you find that a big picture makes the associated feelings stronger and a small picture makes them weaker, well, there is an excellent tool. A tool that you can very easily put in somebody's hands. The client just needs to learn to make her positive self-image and her positive goals bigger, and her fears and anxieties smaller. Once a person realizes that what she does with pictures will control how she feels, that is really empowering.
Sounds work the same way.
But if we change the qualities, making it faster, more high pitched, coming from 50 ft away and so forth, then the experience changes. It is hard to feel bad the same way about Dad's reprimands when his voice sounds like he just breathed helium and he is hanging under the ceiling. Perceptual processing can be used in many situations where other techniques might be effective too. You would probably use it in situations where it occurs to you that the person is limited because of her own perceptions. Well, she always is, but if it particularly becomes apparent to you, it probably means that perceptual processing would work.