What link do we need for avatars?
For avatars you will need the direct link to the picture. For example, if I want a giant smiley as my avatar, I can go and find the picture on a website.
If used, the link above will not give you a smiley as your avatar. The above link is a link to a webpage, not an image. If you want the image, you must got a link directly to the image.
http://upload.wikimedia.org/wikipedia/commons/thumb/8/85/Smiley.svg/800px-Smiley.svg.png
This above link is exactly what is needed. It is the DIRECT link to the actual image.
Note: to get the direct link, you usually just click on the image.