The observing self view allows you to step back and become an impartial observer of your mind’s version of things. Observing your thoughts and feelings from the safe distance of the observing self allows you to see that your mental activity is just that, things going on in your mind. It also helps you observe whether or not this mental activity is accurate, helpful, or contributes to reaching your sexual and relationship goals.
The way you do that is by using Disentanglement (Cognitive Defusion). Disentanglement techniques give you several different ways to step back and take an observing-self view. Many Disentanglement techniques such as The White Board, actually use physical distance to separate you from the contents of your mind (you write that down on the actual white board).