To have a picture of yourself appear next to the comments you make on the discussion boards, you will need to edit your Disqus profile.
1. Login to your Disqus account
2. Visit your profile settings: https://disqus.com/home/settings/profile
3. In the first section, called "Avatar," select "Choose a method"
4. Select "Upload from Computer"
5. A "Choose file" button will appear. Click on it
6. Find your profile picture from your computer files
7. Click "Open"
8. Remember to "Save" your changes before leaving your profile settings page