Clearly you're not an architect nor a biologist. Structural support from the spine in this case is almost nil. Also a jaw must have its hinges---which in this case probably placed mid-abdomen...also, how does she even excrete???
Then again it's an artist rendition. And she must be VERY good at splits ^.^!
Clearly you have no idea who this character actually is. Eldritch demigods don't need to worry about physics, biology or structural support. It's a shape-shifter -- even the pretense of arms and limbs are just an illusion.