The way we sit, stand and hold ourself ‘says’ something about us. When we want to develop self-confidence, for instance, we can use our posture to feel it and be it! It is part of the work in balancing Muladhara Chakra.
It's true, how we hold ourselves will have a dramatic effect on how we feel about ourselves and how we project ourselves out to the world around us. Be confident without arrogance :) ....learn to feel 'good in your skin' and you will go around that world with honesty, dignity, compassion and kindness!!!