Starseeds.info makes use of the facility incorporated in WordPress to use “Globally Recognized Avatars”, or Gravatars for short. Gravatars are a service provided at gravatar.com, where you’ll need to go if you don’t have an account there yet. To quote them: “Your Gravatar is an image that follows you from site to site appearing beside your name when you do things like comment or post on a blog. Avatars help identify your posts on blogs and web forums, so why not on any site?”.
Basically, your image is matched to your email address, so wherever you use the same email, the same Gravatar will automatically appear, saving you having to load your image to multiple websites. You only need to register one account at gravatar.com, which can then handle multiple pictures and also multiple email addresses. The images you load there can be almost any size, but will be cropped and resized as required, so we suggest loading a square image, or one which you can easily crop to be square. Since your avatar will normally only be displayed as a (very) small picture, your uploaded picture need not be more than 200 to 300 pixel per side.