I presume it is because you signed up yourself opposed to being ‘drafted’ by another member.
From dribbble – Anyone can sign up to find, follow or hire designers at Dribbble. However, to upload shots or leave comments, an invitation from a member is required. Invited (drafted) members are called Players. If you wish to be drafted, be sure to check the box marking yourself as a Prospect in your account settings.
Hope that is what you meant and helps.