Of course, the point is that you're not just standing. You're doing Tadasana, Mountain pose, and in yoga in the style of B.K.S. Iyengar, Tadasana is an active pose. B.K.S. Iyengar is one of the best-known yoga teachers and the creator of one of the most popular styles of yoga in the world. His style of yoga is noted for great attention to detail and the precise alignment of postures, as well as the use of props such as blocks and belts. No doubt part of Iyengar's success is due to the quality of teachers, who must complete a rigorous 2-5 year training program for certification.
Alignment follows awareness.
Students learn to focus on the physical and psychological reactions caused by various postures to develop their awareness of mind, body, emotion and spirit. There are three stages in Kripalu yoga. Stage One focuses on learning the postures and exploring your bodies abilities. Stage Two involves holding the postures for an extended time, developing concentration and inner awareness. Stage Three is like a meditation in motion in which the movement from one posture to another arises unconsciously and spontaneously.