I think they must be coal-miners and the guy in the cap has been using smokeless fuels thus depressing the industry they depend on for their livelihoods. The ass-crack is where he hides his rocks; the fingers were lost down the mine on the coal face and the pages are blank to emphasise the futility of manual labour in the modern computer age.
It's really a most amusing, ironic cartoon.
I'm still trying to work out why they have "Pepsi" stickers in the room.
I don't get that part.