Five short lines sketch a woman whose whole life seems to be her job. The speaker calls her "our queen of accounts," which sounds affectionate and a little teasing, as if she rules over the numbers. But the opening image complicates that. "Work is her bark" suggests that her job is a hard outer layer, something she wears like a tree wears bark, protecting her but also covering who she is.
The most striking image is her "thin hand / like a rose full of winter." A rose usually means warmth and beauty, but here it is packed with cold. The hand looks delicate, maybe frail, and maybe tired. The phrase "unhappy for the future" hints that she worries ahead, or that the speaker worries for her.
The mood is quiet and tender, with a note of sadness. The speaker seems to admire her while also noticing what the work costs her. Judging by the imagery, there is something lonely in her devotion.