Vases hold flowers at the Altar.
Flowers are a beautiful representation of life. Since the flowers that will be placed within the vases will hold much beauty - the true nature of reality is that these gorgeous flowers have already begun to die.
Flowers at the Altar have come to represent the Impermanent nature of life.
However beautiful this life is - this life must come to an end.
By learning to live with this reality the individual can free himself from the thoughts of living in a permanent Illusionary scenario.
Flowers at the Altar encourages respect for - The Way.