Bear in mind that these drawings are not depicting Armageddon. They're depicting conditions on Earth, all of which we've seen in various news accounts and films. We've all seen footage of starving people, for example. And photos of bombed-out cities especially from WWII are readily available.
These aren't the gruesome images based on the Society's expectations regarding Armageddon that we have seen in many publications, although I'd surmise that they could swap them in for Armageddon pictures quite easily, with destruction raining from above being the only real difference.