Personally, I prefer Dominic’s version of the initial vision. And I’m not sold on the snake being frightened by her inner darkness, either the idea or how effective it’s possible to get it to be.
I think of it like this. A snake is a symbol of true evil. Because of Rey’s inclination to become even more evil and powerful than Palpatine (evil incarnate) himself, the snake does not harm her and leaves. This imo is much better than shoehorning a force healing (snake) to mentally prep the audience for a later force healing (Ren).