I aspect the poem deals with a pour lady that lives in the worst part of a city, it is full of small streets that smells rotten. Nobody takes care of the lady.

The poem is divided into three stanzas, the first and the third have got six lines, the second one has got five.

The first stanza describes the scene.

In the second stanza there is a simile between the violet half hidden by a mossy stone, that is fair as a star in the dark sky.

In the last stanza there is a obscure image, the lady dies alone and nobody cry her;

the poet  compares his life with the lady's existence and he understands how they are different!

I think the poem is sad, the poet manages to give to the reader a sense of belonging to the scene and so I notes my  luck life respect the girl's life.