We all know that Hashi's isn't "curable", so anyone claiming to have a cure, would certainly be more fiction than fact.
That said, while yoga can't cure Hashimoto's, it can go a long way toward easing some of the symptoms of the resulting hypo. The stretching and relaxing techniques are awesome for the joint/muscle pain that often accompanies hypo. They can also do wonders for the anxiety and depression that also, often accompanies hypo.
When I do yoga on a regular basis, I feel much better, my joint/muscles are much less stiff and sore, I sleep better, etc. Added bonus is that some moves/intensities are great for weight loss.
Agree that her thyroid is pretty prominent, plus it looks like she might carry a bit of "hypo weight".
Hashimoto's is an auto immune disease. Where the antibodies attack the thyroid gland and progressively destroy the ability of the thyroid gland to produce hormone. The ONLY known way to counteract that is to replace the lost hormone capacity with supplemental hormone. There are NO known natural herbs or treatments that have thyroid hormone in them. NONE.
So I'm having difficulties believing that yoga could possibly cure the immune system's reaction that produces antibodies. But that is just my opinion.