This exercise comes from therapy modality called somatic experiencing. Useful for people who experience very intense emotions or who are experiencing the after experience of trauma.  This is very accessible and simple. We advise you to practice this when you are in a calm mood.  You are invited to find somewhere private, comfortable and safe. Invited to notice some distress you might be feeling.

This could be new experience for you and there and no right or wrong answers on how to do this.