How does YouTube Integration Essentials support microdata?

There is a specific microdata scheme for "videoObject"
( which
this add-on can add to your page, which Google can use to display the video
thumbnail next to the search-result. Note that this is optional and can be
disabled in the ACP. Also the videoobject microdata is NOT added for audio-only
embeds or playlists. Google will not always display the thumbnail, this
presumably depends of the relevance of the video to the rest of the page.