You can freely add additional video / image contents to your NFT(s) and make them available to collectors who have this NFT through "Extra".
Sending "Extras" to your NFT collectors
1. Select a NFT you want to send additional content.
2. Click on "..." on the top right inside the NFT 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 NFT will receive an in-App push.