I have a MediaPlayer in my app. When I press F3 on my surface book, a window like this pops out:
How can I set the thumbnail or any content of that window?
The above screenshot is Mediaplayer background mode, when the media app run into background then modify the volume or switch play item, it will pop out. And it is system level. For UWP app we could add Background Media Playback capability for registering this. We could not set this thumbnail and edit the content manually.
For your requirement, I suggest you use CompactOverlay
model to your window, For more please refer this document.