Death holds the banner of the flower of life revealing that he is not the end of all things but a transformation into rebirth.  The horse symbolizes that Death comes swiftly.  Even the King must come before Death and meet his fate.  The child and maid kneel before Death knowing that he is superior.  The holy man prays to him for the same reason.  All three figures represent birth, adulthood and old age.  The sun sets behind the two towers but will inevitably rise again.  The river in the distance shows that life goes on.