I rarely practice this pose....it's a pretty posture but it has zero carry over value into our activities of daily living. Can you name anything that this could help you do better in your day to day life? Perhaps if you are in need of airing your armpits out on a warm day or a novel way of scratching your foot. In fact many of the yoga postures particularly the fancy advanced postures don't make you any good at anything else except doing fancy yoga postures. I want my body to be capable of doing a wide variety of things, not just striking a pretty yoga posture. I need to have the ability to pull, push, lift, climb, throw, squat, crawl, roll and many other movements not necessarily static postures on the confines of a rectangular yoga mat. I often ask myself why am I doing this? What's the purpose? What value and benefits am I getting from this? What outcome am I expecting? I think these are important questions for everyone to ask in many contexts but especially in regards to exercise and movement. For sure the standing leg is having to work like crazy to stabilise and you're working on balance but try holding the leg with the strength of the leg alone without the help of the arm and it makes it a very different posture and it probably wouldn't be very instagram worthy. Passive stretching which this is with some elements of active work is fun and can feel good but try mixing it up with novel and new inputs for your body, mix the same posture up with slightly different variations, different orientations and you have a whole different posture and you're working your body in a whole new way.
Advanced clinical massage therapist and yoga teacher.