Sprite models in game are generated by the script telling the engine to put a various combination of assets (face, body posture, blush) together, in cases where a sprite remains on screen but an element changes (eg. the posture) then the engine will be told to change it with a transition effect - it looks like here that transformation hasn't occurred properly leaving a state of both the before and after. Trying to replicate this on my own side has been unsuccessful.
The best thing to do would be save and reload (so that the script can run over that section again) or if you have the Renpy developer console enabled this can be done quicker with shift + R .
Be warned, elements of this post may have been influenced by my 'West Country Logic'.