It'd help on your post, too, but ultimately we live in a world that contains vagueness. I feel more comfortable not marking a post about a giant washing machine being used to spin news with a blinking SATIRE sign than your post, though, because I can't take it seriously.

That said, they clearly label the site as satire on the 'about' page if there was somehow any doubt that articles about spinning news in a washing machine were not serious.