I love those Luhansk guys! In this case the magnetron is so high powered that you don't even need to build a circuit to light up stuff like gas tubes, everything is excited by the sheer number of microwaves. Those guys produce a lot of good videos, which is even more amazing considering that they effectively live in a warzone (you can here a bomb fall in the distance in one of the videos).
RE: My DIY Passive Mini Radio/Microwave Detector