You can add an avatar to your commenting profile, this will appear alongside your name when you make a comment (instead of the black circle with your initials).
If you have a common name, this is a way to make your profile unique from others who may share the same name.
Log in, then click on your name and a panel will appear containing your profile. Click on the gear icon in the upper right to display your settings. Then, click Choose File and follow the prompts to upload a graphic.