Meditation

Iyengar practices meditation in action.
So, when a student performs yoga postures, the mind learns to become aware of the different parts of the body.

At first, the mind moves from part to part, but with training it learns to become absorbed in all parts of the body evenly at the same time.

One learns to refine one's awareness and penetrate deeper into the body in order to achieve more accurate and thus more effective and comfortable postures. As such, the mind is trained to achieve a meditative state of being.

The reasoning behind Iyengar yoga is that it's impossible to do a pose correctly without strict concentration. Such deep concentration means that you're automatically in a meditative state and rhythmic breathing follows from the effort of maintaining the pose.

Although pranayama is the real key to preparation for meditation, the progress made is applicable to asanas which can be practiced to such a degree of refinement that one meditates in the posture.