It's probably made of cardboard, just to fool the enemy.
And why would they try to fool the enemy with decoy air defense on a roof in Moscow.....
This will probably come as surprise to you, but New York, Washington etc also have air defense systems around them
whataboutwhataboutwhataboutwhatbout
But ok, let's play your little silly game.
Did Moscow not have "air defense systems" until now? And the best they can do is lift a vehicle-based SAM on top of a building?
I can stop laughing just thinking about the logistics of it... missiles, crew, fuel, etc. I'm guessing someone at the MOD was tasked to "protect the Kremlin from Ukrainian drones" and just went for the галочка, not too concerned with how things actually work.
