Of course most of you don't get it...
In re: to many of the commentators--yes, Carl's Jr. is a fast food chain out here in the west and on the west coast, too: The "big breast sandwich" flashie parodies the recent Carl's Jr. commercial on tv. I lived in NY for a while as well, and I understand why many of you are puzzled (since you're probably more accustomed to seeing White Castles and such everywhere).
But a word up to the rest of you who claim not to see the dark humor: Of course you don't get it! You dumbasses! If you are so unenlightened that you still eat meat, of course you don't get the joke!