What images are use to emphasize Lucy's pure exquisiteness?

Lucy, the subject of "She Dwelt Among the Untrodden Ways," meant a great deal to the speaker, although her worth was never recognized by anyone in her life. The reader is made aware in the final stanza that Lucy has died and that "few could know / When Lucy ceased to be." Such a sentiment of loneliness is compounded by the fact that Lucy was a rare beauty in her life.
The speaker compares Lucy to "A violet by a mossy stone." This metaphor accomplishes two things. First, it lets us know Lucy's beauty stands in sharp contrast to the world around her, as we are presented with an image of a purple flower against a dark green background. Lucy is presented as a beauty that would naturally captivate one's attention. Second, violets are used to both symbolize innocence and loving thoughts, so Lucy is thus presented as an innocent "maid" in her loveliness.
A simile is also used to capture her beauty: "Fair as a star, when only one / Is shining in the sky." Most people take a moment from time to time to note the definite beauty of stars. However, Lucy's beauty outshines an average starry night; her beauty is singularly beautiful and worth individual attention. The speaker again uses the word "fair" in this description, connoting a sense of purity in her beauty.
The real mystery in this poem is how a beauty like Lucy could live a life without praise and with few who loved her, slipping away almost completely unnoticed into death.