Re: How about a /working/ demo?
C:\Users\Peter>docker pull gaetan/dockercraft
To execute docker pull you need to have installed Docker and to issue commands in the Bash shell that's installed with it.
Docker doesn't seem to live very comfortably on Windows. Not only do you have to use the shell (which annoyingly seems to have replaced the Bash shell that comes with git) but it seems to work with a very memory-hungry VirtualBox VM.
The Minecraft thing looks like a gimmick. Anyone doing the kind of job that requires Docker should be able to understand it without recourse to a game that really has nothing to do with it.