Depending on your philosophy, a human corpse can be anything from a sacred vessel to a sack of rotting flesh that might as well be disposed of in the nearest Taco Bell dumpster. But I think even the most cynical among us would agree that a random cadaver shouldn't be used as a prop in a wacky Christmas card, given that it would both offend the family of the deceased and make the med student's family worry about his mental health. The past, though? It didn't give a f**k. It didn't even have to be a special occasion for them to play with their corpses.
That's from 1906, and there's nothing being celebrated beyond "Hey, I just realized that I have access to cadavers, and also have a disturbed sense of humor. Maybe later I'll make it look like a couple are just suckin' my dick."