You can freely add additional video / image contents to your creation(s) and make them available to collectors who have this work through "Extra".
Sending "Extras" to your creation holders
1. Select a creation you want to send additional content.
2. Click on "..." on the top right in the creation page, select "Send Extras".
3. Edit the details for the extras' you're sending.
4. Once it's published, all of the collectors who own this creation will receive an in-App push.