Us lecturers, we just have to critique all the time!!
You’ve photographed yourself from a very close proximity to the camera, which means you’ve had to use a wide angle lens setting (20mm). This tends to make some features of the face stand out – such as your nose. You’ll find that a longer focal length, say 70mm, will lead to a much more flattering view. (yes, if people think you’re pretty in this shot, just wait ‘till you make this change!).
The aperture is small at f3.8, which helps to remove you from the background, but this will defocus other facial features because you’re so close to the camera. The lighting is good, with no nasty shadows, highlights or washed out detail.
You’ve got your eyes in focus, which is the most important thing in a portrait. I like the hair failing over your eye – helps to stop the picture looking too symmetrical. The large pupils in your eyes have caught some nice reflections. Nothing in the background is overly distracting.
A nice informal portrait – well done.