How does the repetition of "one " at the beginning of the first two lines add to the meaning?

The poem reflects the singular through the first two lines. The artist seems consumed with the singular: One face looks out from all his canvases, One selfsame figure sits or walks or leans: Here, anaphora of the word "one" and parallelism between these lines makes the poem reflect what it describes.

One of the

One you are