I think it’s a representation of her spirit; it is on her fake cutie mark.

Fluttershy’s ghost?

“I fight and I fight
Just to keep the spark alive
But if there’s nothing on the other side
Why can’t I leave well enough alone and go to the light?”

So if this was supposed to be a representation of how her emotions regarding the situation, in particular her anxieties, are acting as a guiding force, are they now guiding her towards the escape from the situation? Like “I’m constantly afraid, in pain, hungry, this feels bad and I should seek separation from whatever’s causing me these troubles” and as such would be leading her away from Opaline and her abuse? Because if so, you’re a bloody genius with this symbolism. Here she isn’t thinking, but rather feeling and letting that guide her out, as opposed to thinking and trying to rationalize the abuse.