Video banners are different from Video widgets in many ways. Unlike video widgets which play the video inside a Flash player that's fixed in size, video banners are designed to efficiently insert video content on a commerce page without taking too much space on the page. Below is an example of a video banner. As you can see, the banner itself is directly embedded in the page, with a thumbnail for the video or a static image.
When clicked on, banners expand into an overlay where the video is played: