Google this week announced an upgrade of the Active View metrics in Campaign Manager 360 and Display & Video 360.
Google says the upgrade will be an improvement of the Measurable Impressions and Viewable Impressions for some Display & Video 360 YouTube inventory.
Google will display a notice for all impacted clients with an estimate of the change. The notice will display in product until around Aug 15th, and the changes will be complete the week of Aug 16th.
Active View is Google's technology that measures if an ad is viewable.