It is fake. VNC is written all over it
I don't think it is.
I've made HackBooks by installing OS X on different laptops. It isn't difficult if you have some computer knowledge and access to the internet. There are many different forums available that will guide you through the process. It just requires some sort of boot loader to get Darwin (the base of the OS, based on BSD) to load. Then some modified kexts to get around the issue of it being non apple hardware and you're golden.
WiFi is the normal stumbling block and I can see in the video that a USB ethernet adaptor is being used.
It's a shame we don't see it boot, but I am 99% sure this is a genuine video.