This is an example of a Video post format. By selecting “Video” from the format meta box on the post, it will then have a video post format. By doing this, a couple of things happen:

A video icon is applied over a featured image if set
Grabs the first video embed and features it at the top of the post

Videos can be added to each post by simply inserting the video URL from one of the allowed video embed sites. WordPress will automatically embed the video to the size it needs to best fit the content area.