Having a dedicated workspace in your backyard will allow you to create a very important mental and physical boundary between home and work.
I don't know, it seems a little cramped. Even a bit... silly? I think I'd be self-conscious if it's be public spaces.
Probably not exactly cheap either. But then if you're really strapped for a little privacy when working, it may be the thing. And doing a bit of research, it's clear that quite many people are really keen on getting such a thing.