Here's what to do:
Apply to the SIGCHI.be LinkedIn group. If you do not have a LinkedIn account, you will be asked to create one.
Click "Accept Invitation"; button in the link above. When you do that, your group membership request will be pending until we validate it, usually within a day or two.
You will receive an email once your membership request is approved.
Afterwards, the group logo will appear in your profile under the My Groups link.