I think Rey represents a sort of older, more humanist view of the world. The sac is a throwback to this. It also lends him a sort of imagery, as a worker, a man who made it on his own. The girl, is the new world, of terrorism, nudity, frigidity. At the end, the two have joined. He has given up his sack, she has given up her virginity. Their game is over. The end scenes are shot in silence till the very end. The explosion, perhaps it indicates Bunuel's negative view of the future.<br /><br />I always get thrown off by these great 70s movies. The color printing is so bad, it looks comical. Why do you have to put 10 lines of text? That's daft.