This is a depiction of how this universe breathes through this vessel. One way when we breathe out and the other way when we breathe in. We can determine the direction of the energetic flow with an intention to direct our attention. If you continue breathing in then the physical heart will begin to pound to circulate the oxygen in the blood through out the body, and eventually you will faint as no oxygen reaches the brain, I guess.
When you breath out completely a vacuum appears in the lungs, which sucks in the air. A bit like the vacuum that this spoon creates by sinking into the soup. Pay attention to the fat drops on the surface of the soup.
So if you breathe out completely and continue breathing out then no fresh oxygen can enter into your lungs.
To lived a balanced life, one can pay attention to one’s breathing. Where does your emphasis lie? where do your place your center of gravity. Your can learn a lot about yourself and thereby the universe by paying attention to your breath!