NEW MOON: The type of flower it is described to be is a red ("bleeding") tulip. It was chosen by the publishers because the tulip is most commonly a symbol for true love, worthiness and forgiveness.
ECLIPSE: The ripped ribbon is suppose to symbolize Bella, torn between Jacob and Edward.
BREAKING DAWN: The two chess pieces represent Bella: the pawn is human Bella. When the pawn reaches the other side of the board, it can become a queen. So the queen is suppose to be vampire Bella, which is much stronger than human Bella.
HAHA actually, u got one part right!
the other part is, that the type of flower (I forgot the name OF the flower) but I DO know it means something to do with Darkness or something, and it revolves around Bella's darkest time (so far-har har) and how her broken heart "will never mend until she has Edward" so yea...