Asana means "seat". It also means "state of being".
When we do asana, or practice asana, we are invoking certain qualities which are inherent and effortless to that entity which holds that "seat" or "state of being" as its natural state.
Balasana = baby pose: This reminds us that we are interconnected and a "baby in mama's arms" at the end of the day. This asana is humble, innocent, pure, and effortless. It is close to the divine, and it is-- as we all are at our core -- unhidden, not striving, and reflective of truth at any given moment.
Tadasana = mountain pose: This asana reminds us that patience lives within each of us. Who could possibly be more tolerant than the mountain? Tread upon, taken for granted, exfoliated (in the truest sense), and steadfast for a really, really long time... These qualities help us calm the nervous system, awaken tolerance, surrender, and stability, while at the same time being strong, foundational and grounded.
The yogis of ancient times found that holding specific positions opened particular channels for life and conscious awareness to flow. The yogis also found that by strengthening, training, and directing one's discipline through asana practice, steadiness develops. When a body is steady and conscious, less disease enters and more life force flowing through.. a.k.a. more prasad (blessed nourishment) is bound to be present.
The advanced yogi learns that it isn't what we do as much as the consciousness we bring to what we do. When we are conscious, life goes smoothly. And who doesn't want that?