Arc has this feature that is wonderful—automatic PiP. It's a setting that when turned on, works like this:
Let's say you have a video playing in a tab and you navigate away from that tab, Orion would autmatically put the video in the last tab in PiP mode.
If you navigate back to that tab that is the source of the video, Orion pops the video out of PiP and back into place within the tab.
The PiP player would also have controls to close the player, minimize the player, play/pause, go back/forward 15 sec., and there would also be a button that jumps the browser back to the tab that is the source for the video and pops the video out of PiP mode.
The PiP player would also be able to be moved via a two finger drag gesture on the trackpad, and is able to be resized via a pinch gesture.
This is great for multi-tasking, and allows the use of PiP in a very easy and intuitive way. It can also be turned off for anyone who doesn't like it, or turned on for anyone who wants it. It's great because you don't have to think about it and just makes things easier and smoother for a better user experience in my opinion. I've seen a lot of folks talk about this as a highlight feature of Arc as well.
I thought it was easier to record a video uploaded here.
Here's another video showing how resizing and moving the PiP window around works.
I should note that I've also tested what happens when you start one video in PiP, navigate away from that tab, then start another video, and repeat that process. What happens is the most recent video that is played gets put in the PiP player. When that happens, the audio from the video that was replaced with the latest is not muted and the video isn't paused. It's only moved back to the source tab.
I hope this can get some serious consideration. It's a fantastic feature.