Instagram is a fun place to look at yoga postures, and you can find plenty of beautiful young people in skimpy clothing doing seemingly impossible things with their bodies. However ... although I have a great appreciation for physical beauty, alignment, and a well-composed photograph, there are many, many "yoga" accounts on IG that are counterproductive to our understanding of Yoga as a practice.
For starters, please don't use Instagram as a reference for what you think your body should be able to do, or aspire to accomplish. Many posts carrying the hashtag #yoga are actually displaying some form of contortionism, which is more of a sport or perhaps a performance art that has nothing to do with real, capital-Y Yoga. Contortionists are certainly sensational to look at, but they are not necessarily Yogis. They are often people blessed with extraordinary flexibility who are being paid to model yoga clothing or products, and their postures are designed to grab your attention for commercial purposes.
This "posture" in particular seems to be very popular lately, and it's one that drives me a little bonkers:
That crease in her back is the "weak spot" where thoracic and lumbar spine meet, and bending it in this manner introduces extreme stress on the discs. This is the spot we try to *avoid* stressing during backbending -- ideally any extension of the spine should be distributed evenly along its length, not concentrated in one spot.
This model may be well trained in her physical discipline and know exactly how to avoid injury, so I'm not here to judge -- but please know that for the vast majority of humans on the planet such bends are unsafe and inappropriate. As are many other extreme demonstrations of flexibility. Please don't aspire to them, no matter how much the ego goads you into thinking you should.
Often I also see text accompanying such poses that asks the viewer, "Can you do this pose??" Do not engage! Yoga is not a competitive sport, and I say that as someone who once competed in a "yoga tournament," back before I knew better (I took 3rd place, TYVM). This is why I encourage participants in my classes to never apologize for their body's inability to do something. I can't count the number of times someone has said to me after class, "I'm sorry I couldn't do X," or "I'm sorry about my alignment in X..." OMG, stop apologizing! (Although please don't apologize for apologizing, either. It's just that darned ego again.)
Your job is not to impress the yoga teacher (or anyone else in the room). It's the teacher's job to help all students, regardless of physical condition, learn how to honor, enjoy, and make peace with the body, and to reveal its wisdom.
The body is your Soul's vehicle in the physical world, a learning instrument through which it can experience and evolve. The goal is Self-realization; that's what Hatha Yoga (the practice of physical asanas) is designed to facilitate. Whether you're bendy or not is irrelevant. Sure, it's absolutely a part of asana practice to explore your body's capabilities, and to enjoy a sense of wonder and accomplishment as you refine and deepen them, but this is a sort of side-benefit. As I mentioned to a class just the other day, I have practiced alongside paraplegics and amputees; people with neurological ailments and elders who couldn't touch their toes.
It Does. Not. Matter.
Why? Because physical flexibility is simply a result of asana practice, not a goal. To show it off as some kind of achievement may be gratifying to the ego, but will do nothing for your spiritual evolution. Yoga means "union," and Yoga as a practice is dedicated to unifying the individual Soul with the cosmic Divine using the body as a "foil" of sorts. An inflexible body is not a problem. An inflexible ego is.
Carl Jung wrote (as quoted by Yogananda in Autobiography of a Yogi), "(Hatha) Yoga practice ... would be ineffectual without the concepts on which Yoga is based. It combines the bodily and the spiritual in an extraordinarily complete way." Yogananda comments further: "Hatha is useful, and produces spectacular physical results, but this branch of yoga is little used by yogis bent on spiritual liberation" (Autobiography of a Yogi, 13th ed., p. 254).
That said, one of my teachers once commented that (paraphrasing), "Asana is a sort of 'bait' that tricks people into embarking on the spiritual path." So I can't totally discount the usefulness of Instagram "yoga" accounts to the extent that they generate awareness of and interest in Yoga as a practice. If an ego gets hooked on the idea of having a "yoga body," only to later discover, through much asana practice, that such a body is totally meaningless to the True Self, then Mission Accomplished. Then we perhaps can consider the idea that the Divine was using egoic vanity to "catch" Itself some real Yogis, all along.