Symbolizing ephemeral beauty, cherry blossoms or "sakura" have great cultural significance to the Japanese.
Cherry blossoms are symbol of the ephemeral nature and beauty of life in Japan, and they have become symbols of Japanese culture around the world. They are frequently depicted in art and on common goods such as stationary and dishes. During World War II, pilots painted cherry blossoms on the sides of their planes in the hope of being reincarnated as blossoms.
The great import of the the cherry blossom explains they heavy use of pink on this card, a color that Japanese postcard artists seem to have used with the greatest frequency.