Comment 2 for bug 2022954

I think this is expected, so more of a feature request than a bug.

gnome-shell isn't really a Terminal Server like you'd find on Windows. And it's not a remote desktop server like legacy X11. It's primarily a local desktop which can be controlled by remote protocols. But in order to have a desktop to control it needs to have a size, hence a monitor plugged in.

Seems totally reasonable that gnome-shell should support the headless case though.