Once you’ve chosen to look at a card, you can continue to swipe upward to see all the alerts and Google Now notifications that have piled up. Besides the cards shown here, I’ve also seen alerts for baseball scores, travel times, Twitter activity, a friend’s birthday (via Facebook), the weather, and an invitation to buy something from Fancy (an early Wear app coded just for the smartwatch OS).
Once you kill a card by swiping it to the right, it’s gone forever. Google engineering director David Singleton told me that user studies indicate there’s no outstanding reason to maintain a card history. He also said Android Wear won’t expose Google Now cards for information that doesn’t fit the context of a wrist wearable—for example “What to watch” TV recommendations.