You can almost read "Portrait d'une Femme" as a long inventory, or laundry list. The speaker outlines a whole "sea-hoard" of different types of merchandise, both manmade and nature-made, tangible and intangible. Instead of describing the "femme" directly, the speaker focuses on the things exchanged between her and others. What do they pay her? What does she pay them? What riches does she store? The woman becomes defined by her surroundings and interactions with other people (men) rather than any essential qualities. The speaker concludes that there is nothing that's quite her own.
The "femme" is a very wealthy woman, but the speaker is trying to tell her that her wealth is useless, that other things are more valuable than money.
This poem criticizes the idea that a person can be defined by their possessions. It argues that a fixation on material wealth leads to the loss of an individual's true identity.