The main problem is the awkward perspective on the pose. You’ve got the horse body almost side-on, but the human torso at a 3/4 view. Either have the horse body going into the image plane more, or turn the human torso to the side more. Also, the hair braid is just hanging there flat without appearing to come from behind her head to over her shoulder.
 
The forearms are a little on the long side, and the shoulders are ill-defined (the right arm appears to join at the chest, while the left shoulder is too rounded).
 
The face needs a little work - the mouth is a little wonky, and if you were going for a sneer then it needs to be reflected in the rest of the face too (bring the lower eyelid under the sneer up, put a couple of folds around the raised area of the mouth). Also, make the glasses bigger - they’re quite large in the show to avoid obscuring her eyes so much,
 
The outlining is inconsistent - you’ve got parts of the body with thick outlines, while the hair, tail, back and shoulder/neck area aren’t outlined at all. Either use outlines consistently, or don’t use them at all (and use shading to define shape). You are at least using dynamic lines though (different thicknesses to indicate depth. weight and shading), but try and keep them neat.
 
There’s nothing wrong here that can’t be fixed with a little practice and attention. Do some life drawing to get a better grasp of posing, anatomy and perspective. Pay particular attention to how to do foreshortening - your posing looks like you’re straining to avoid having to draw foreshortened limbs or bodies.

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