Your lovely child seems to be fascinated by her image on the mirror and tries to communicate with the image. Your daughter is still not able to identify the image as her own as self-recognition happens in the second year of life. This fascination for the face is more to do with her social development as she loves the fact that there is another child who appears every time she looks at the shiny surface.
What you need to know
For your child at this stage staring at the image and trying to connect with it is more a fun, social activity and not about self-recognition.