There is nothing wrong with your mouth, however, your eyes appear to be staring, your upper eyelid appears high, possibly due to the low angle of the shot or, maybe, your eyebrows were raised? I'd have preferred to zoom out slightly to get all of the moon in, with a little space around it.
Nevertheless, you should probably bear in mind that, although they say Beauty is in the eye of the beholder, it doesn't hold true if you are looking in a mirror at the time, only when observing from afar. Your top seems a much better fit in this photo.