If you have a video hosted on a website (YouTube, Vimeo, etc.), you can embed that video into your storefront for engaged couples to view. To embed a video:
Click the "My Storefront" tab
Click "edit" next to the "About" section
Click "source"
Paste the embed code (found on the hosting site)
Click "source" again
From here, you can click on the video and center it if you wish. If you wish to embed multiple videos, simply follow these steps each time.