You need to know what pictures/videos you are going to use in your production. So of course you need a video plot to know this information. The video plot is similar to the cue list as it should list all the points in the script where a video is needed and also describe in some detail what the video or picture is.
When you have all your pictures/videos ready you have to show them to the director and make sure they are what they want. The video parade will help to show these videos. Again this is normally done on Tech Day.