There are two types of library cards: master cards and minion cards. Minion cards are used by the vampires and allies you control. (Both vampires and allies are minions.) Master cards have a grey stone background; different types of minion cards in Vampire: The Eternal Struggle have different backgrounds to help you tell them apart. Any library card not explicity named as master card is a minion card.
Each library card has symbols on the left side for the card type(for minion cards), the clan symbol or discipline (if any) required to play the card, and the cost (if any) of playing that card. You'll notice that Blur has a discipline symbol (celerity) on the left side. This means that only vampires with the celerity discipline may play Blur. Also on the left side of the card is a blood drop with a number in it. This indicates the amount of blood that the vampire must burn or spend to play the card. If this symbol had appeared in the bottom left side of the card, the methuselah would have been required to burn pool equal to the number to play the card.