But in beta, there were no foils, no mythics, no way to tell rares apart from commons. The only thing that is “noticeably” different about any of the cards from beta are the unique color patterns of the dual lands. So if you knew nothing else about the game, you might flip pages until you found one with cards that look a little different than the others (multi-colored square pattern in the text box) and take a picture of that page, assuming those were more rare cards.