At the end of every lookbook campaign you have the option of adding a "back page". This what a completed optional back page can look like:
You can chose to display all or just some options on your backpage. Your brand logo, description, social media and contact info can be displayed/hidden.
You can enter this information either during campaign creation or by visiting Brand Details within your My Account area.
3rd step in Campaign creation is enabling and customizing your backpage.
Your Brand details area is where you can enter all your contact information. Special note you can also enter HTML/CSS to customize your description :)