Video settings referring for the embedded videos into the popup. This can come from Youtube, Vimeo or even self-hosted one.
More Settings / Videos
The Automatically play videos parameter means, that the emdeded video will start when its layer appears. By disabling this option, you will need to click on the play button manually, if you would like to see the video.
Creative Popup can Pause the pageshow while it is playing, or even pause the popup permanently.
With the last parameter you can set the quality of the Youtube preview. If a grey thumbnail image appear for the video, you need to decrease this value.