the shallow DoF and tight focus make for a nice impact on this photo, the subtle catching of light on the eyes is a also a great touch. Self-portraits however will not score well in free-studies, especially ones with the camera visible, but that doesn't take away from the niceness and rawness of this photo
so, mirror self portraits are common, dime a dozen things, generally. This is, however, WONDERFUL!! lighting, focus, dof, the walls/tones on the sides, and the blown backlight behind you are all masterfully done. The lighting on your face, hair, dress is warm and natural, and your expression is serene, calm, not overly warm or overly serious. some might say you should have not cut off the top of your head, but I will disagree--the vertical lines in this image echo from one side to the other, and your straight hair is one of the lovely echos--having the hair run nearly directly out of frame keep that vertical element working. so nicely done. the oof camera is good--it is not the subject, and too often in these kind of shots dominates the image. Your choice of clothing, background, and lighting keeps it low key, and one might not even suspect this is a mirror shot, but simply someone snapping your picture as you raise or lower your camera--cannot easily tell the image is reversed, since the camera/lettering is oof. 9
Nice, intense look. I think the technicals may let you down a bit. Your WB went a bit red, and the highlights are too far to the right in your histogram.