One of the major drawback of either the Lightbox Photo Viewer or the Video Viewer in full screen mode is you cannot do anything except looking at the.
Though for many it makes sense but for videos you might like to choose mini player and not full screen. This means if you have a long video to watch which you need to buffer or just want to keep it running on the side, Facebook does not support it right now.
However If you are using Chrome, you have a chance to get this feature using Facebook Video Player extension. Once installed, next time you play any video on somebody’s update, the whole thing opens up on right top where you can see the status, video and comment all in one place.
Next you can keep browsing your Facebook News, Updates, Watching Photos etc. This makes sure that you do not miss any interaction while watching the video.
You also get a close button which just closes the overlay however if you are still on the same timeline from where you picked this up you will not be able to see it unless you make a refresh.