All video ads are eligible for weekly updates if there is new data available. For example, if you select the Parade of Homes design and post a new listing near the ZIP codes your ad is targeting, then that listing will be added to your ad campaign the next time your ad is scheduled to be updated.
The Market Guide design will always update each week. The points on the graph compare weekly data across months. For example, if the current week is the second week in August, then the stats displayed for the other months on the graph are for the second week of those months as well.