Just like its name, this is a fun pose. Depending on your flexibility, you may be able to grab both ankles with opposite arms, while on your side. If not, reach for wherever feels right for you. Or, just reach for the bottom leg behind you, and keep the top leg lying naturally.
As with any unilateral pose, be sure to hold both sides for the same length of time, unless your yoga therapist recommends a deeper stretch on one side to balance things out.
Cat pulling its tail, while very different from the twisted dragonfly, http://thenamastecounsel.com/wisted-straddle-dragonfly-2/ activates the same meridians: Liver, Kidney, Urinary Bladder and Spleen.
This is a nice pose to generate a deep stretch in the IT bands, which contribute to hip flexion. It also is a great stretch for the quads, making it a nice counter stretch for poses like seated forward folds.
For more about benefits of Yin Yoga in general, visit my blog spot, www.TheNamasteCounsel.com/yoga-blog, and enter the words Yin Yoga in the search window. As always, consult your yoga therapist to determine which poses are best suited for your particular physical and emotional needs.