A little menu should show up and you do the following:
There's should be a circle next to Use Gravatar, click on the circle and a black circle should show up in this circle, this means you are now using Gravatar for your avatar, now fill in [email protected] and you press Test, the image should show up, now you press Okay, and the menu should dissappear, now scroll down and you should see Save Changes:
Now you're good to go if you followed the steps correctly!
(And yes the avatar was a bit too big so I resized it)