This poem paints an obscure image of a woman, beginning with a handful of sea metaphors describing her and her interactions with other people. She has been living in London for at least twenty years ("score" means twenty). On line three, "bright ships" is likely a metaphor for the people that surround her, leaving her abstract "fees" like ideas and gossip. "Great minds," probably philosophers, writers, or others of that stature who "lack someone else" tend to seek her out. Even though she is always "second choice," she prefers this life to being stuck in a dull marriage.
In return, she gives theses people "facts that lead nowhere; and a tale or two," which aren't particularly useful. The poem characterizes the woman's "riches" as decorative and gaudy. Despite this ongoing exchange, there is nothing that truly belongs to the woman, but this transience defines her. The poem finishes with the line "Yet this is you," which suggests that she would not be who she is if she had things to call her own.
Pound was certainly not the first to title one of his works "Portrait of a Woman" or some variation; the title is an homage to Henry James's novel "Portrait of a Lady." T.S. Eliot and William Carlos Williams also composed poems with titles based on James's. To this end, a male poet with a female muse is a common poetic trope. In Pound's "Portrait," the poet cloaks his female subject in tattered mystique. Critics and historians have suggested that Pound's particular muse for this poem was Florence Farr, a British actress and writer.
Pound wrote this poem in blank verse, rather than the free verse he was frequently writing at the time. Blank verse is written in iambic pentameter, a rhythm most commonly associated with Shakespeare where each line consists of five sets of two-syllable "feet," or ten syllables in each line. In iambic pentameter, every other syllable is stressed. Though the vast majority of lines in "Portrait" follow this pattern, there are a few scattered which are either shorter or longer than ten syllables. There are a number of reasons why Pound may have done this, however, as it is common for poets to vary meter in order to draw attention to specific lines. Therefore, it is likely that Pound wanted to emphasize the lines that have irregular meter.
In the very first line, the speaker associates the subject with the sea, an extended metaphor that continues throughout the poem. He references the Sargasso Sea even though it is far from the subject's residence in London. However, the Sargasso Sean is known for collecting seaweed and debris just as this woman is known for collecting knowledge, gossip, and ideas. The sea also symbolizes this woman's reluctance to tie herself down; the sea flows on and on forever, collecting whatever it finds, and the woman would rather do the same rather than dropping anchor somewhere. The ever-changing sea belongs to no one, just like this woman, and at the same, nothing and no one belongs to it/her.
Pound reveals his fascination with economic theory in this poem through all the references to commerce and trade. He frames the woman and her ephemeral relationships as business interactions. "Great minds" and "bright ships" seek her out and provide her with gossip, knowledge, and ideas in exchange for the gaudy, decorative tales and useless facts. The setting fits with the commercial theme as well; the Sargasso Sea is located on an important trade route to the Caribbean, and London, of course, is a major global trading hub.
The speaker finishes by emphasizing that despite all the tidbits this woman has accumulated, none of it is truly her own. Does that make all of it worthless? Does that mean these great minds are sharing their secrets with others as well, so they are not uniquely hers? There are many possible interpretations for the final few lines, though the ephemeral nature of the woman and her life is apparent. The ending of the poem is purposefully vague.