So essentially the WSL in reverse?

I'm kind of surprised you can "run Windows" in a Docker container at all. Isn't the fundamental restriction of Docker that all containers share the same (linux) kernel? Is there a way for docker to inject a "translation layer" somehow that makes it look like an NT kernel for the Windows processes?

The container runs a virtual machine using the host kernel's KVM device. Windows is then automatically installed inside said virtual machine.

https://github.com/dockur/windows