I can't decipher these avatars. Not sure what I picked. Anyone have a clue? I know, completely off topic. Lol
Lol, I can't tell what yours is, but you can go to your profile and click on your avatar. You'll see a drop down menu and you can choose from different categories. I think they'll eventually change this to where we decide what personal pic goes there. Hope this helps!
If you want to use the premade avatars under the "From the Community" section of avatar selection, you can hover each image in the for a moment to see it's label. Like the blue circle one you have atm is "dessert" (presumably ice cream). However, now that you're ranked "Rewards Hunter" on the forum, you should have the option to use a different image by either using "Upload an Avatar" link or going to "From the Web" tab on the same account page.
That avatar is called Dessert and looks like a bowl of ice cream. 🙂
The other two answers tell more about how to change this.