A profile pic and an avatar are different. Your profile pic looks great! To add an avatar, select 'Edit Avatar" and it will take you to a new page. From there you can choose one of ours, or you can scroll down to where it lets you upload your own. The avatar file must be smaller than the profile pic. The maximum size of your custom image is 110 by 150 pixels or 14.6 KB (whichever is smaller).
I hope that helps