What is the need for this feature?
It can help the users in various kinds whether it is a Gamer or a normal user but the one big aspect for this feature is it is going to boost users productivity with their work. For an instance if a user is working on Notepad and he/she wants to visit a website continuously. It would be very helpful if he/she has a tab pinned on the screen as an overlay. Or maybe for people who like to stream YouTube while working on a project and they really wish if it can work in picture-in-picture mode so they can do their work while not compromising on fun.

I have designed a UI for this feature and how it can work. So please support the work if you like it. I am working on a prototype for it.
Thank you