Well, something new has been added. Playtest cards exist as stickers on old cards, right? And sometimes, enough of the old card is visible that it's identifiable. So we've taken four playtest cards that we think have identifiable original cards. It's not just "Guess the Playtest Card"; it's also "Guess What Card the Playtest Card Is Made Out Of!"
Here's how this works. We're presenting the playtest-stickered cards. You can either move "back", meaning that you want to see the card before it was stickered, or "forward", meaning that you want to see the printed version of the playtest card.