What is being compared in the poem Unfolding Bud

The poet Naoshi Koriyama in his poem Unfolding Bud compares a water-lily bud to that of a poetry.

Explanation:

In his poem he uses significant metaphors which stands out and is made attractive to the readers.

He describes poetry with that of a growing plant.  

From bud to a growing plant he shows how poetry has developed over the ages.

Also, until the flower opens, we wouldn’t know how it would look. This is an awesome comparison which means the beauty of the poetry is unveiled as an when we read it on the way.