That would be your avatar.
To edit that, go to the menu bar towards the top of the stratics page.
You will see:
User CP, Faq, Memers List, etc...
Click on User CP
Once there you will see the control panel. Down on the list and there will be Settings and Options section not too far down. First link is Edit Avatar, go there
Click custom avatar and then you will be able to either link to an avatar picture or upload one for your computer
