Remove the giant rectangular panels on the stream window for voice calls

When you're in a voice call, each user appears with a large rectangular background behind their profile picture. This takes up a lot of space, especially when multiple streams are running in a call with several people.

It might be a better idea from a space-saving perspective to lay out everyone's profile pictures on the bottom and then put the streams on the main portion (see attached sketch for demonstration). There also might be better alternatives but this is what came to mind at the time of writing.