<http://schema.org/description>
"It's no secret that YouTube already lets you scan ahead in time and view thumbnails of videos. But this is only on the video timeline itself - either on YouTube.com, or when it's embedded ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/apps/2012/07/10/this-chrome-extension-lets-you-view-multiple-preview-thumbnails-on-links-to-youtube-videos/>