You know that it is a fake mockup because you are ...?
Article:
Obviously we only have the picture to go on, but it looks as you would expect for a compact nuclear warhead, said Jeffrey Lewis, director of the East Asia Nonproliferation Program at the James Martin Center for Nonproliferation Studies of the Middlebury Institute of International Studies (MIIS) in California.”
Because I know more than a little about nukes. Had a roommate who now designs them. We talked a lot. His goal: design a gigaton or teraton (three stage) nuke to blow a city or planet killing asteroid out of the sky.
Some of his designs were terrifying. And that was 30 years ago.
I also have a couple degrees in engineering/physics.
But those aren’t required. It’s easy to spot the manufacturing defects just on the surface of the mockup that show nowhere near the precision required for a functional compact nuke.
For example: Look at the welds on the “disk” second from the center at about the 7 o’clock position...