WhatsApp has updated their desktop web extension to 0.3.1846, bringing a feature which has been available for some months on iOS and Android.
The app now has limited support for Picture in Picture mode for shared videos.
This allows users to view a shared video and still continue chatting, including switching to other chatrooms.
The feature is not available yet for all videos, only those shared directly via WhatsApp, with the company still testing support for Facebook, Instagram, YouTube and Streamable videos.
If you want to download WhatsApp for Windows, you can get it from this link.
Via WABetaInfo