The poem begins by describing the pearls and their place on the speaker's neck. The structure of the first sentence juxtaposes the ownership of the pearls with their location. By identifying the "her" of the first sentence as "My mistress" in the second, the speaker clarifies the relationship between the two. She describes how she wears the pearls for her mistress until evening, when the speaker will brush her mistress's hair.
The speaker's mind then turns to her thoughts throughout the day, which seem dedicated to imagining what her mistress is thinking. She imagines her mistress resting in what she calls the Yellow Room, deciding what dress to wear for the evening. "She fans herself/whilst I work willingly, my slow heat entering/every pearl," the speaker says, bringing her mistress out of her imagination and into corporeality. This stanza ends by describing the necklace as a rope, slack but very present around the speaker's neck.
In the next stanza, the speaker is again fantasizing about her mistress, imagining the party, where the men she dances with are perplexed by the speaker's scent under her perfume. "She's beautiful," the speaker confesses without reservation. The pearl necklace again makes an appearance, bearing the speaker's smell.
The next stanza begins with the speaker dusting her mistress's shoulders with a rabbit foot. The speaker perceives the moment as sexually charged, looking at her mistress blush and imagining her sigh. She catches a glimpse of herself in the mirror and sees that sexuality reflected in her "red lips," which "part as though I want to speak."
We then jump to nighttime, after the party has ended. The speaker still imagines her. "Undressing,/taking off her jewels, her slim hand reaching/for the case, slipping naked into bed, the way/she always does...." the speaker says, hinting that, though she may not be with her mistress now, she has seen these bedtime rituals before.
The speaker turns her mind to the pearls, which still are losing some of her warmth in her mistress's room. The speaker "burns" with the pearls' absence.
"Warming Her Pearls" voices the thoughts of a woman from the Victorian era, describing the curtailed yet still, seemingly, sexual relationship between a maid and her mistress. The voice is just slightly anachronistic; Duffy does not go out of her way to make the voice clearly that of a different era. Nevertheless, the poem's form reflects the severity of the era, while the language and the speaker push the boundaries of that severity.
In this poem, the pearls take their importance by acting as the site of intimacy between the speaker and her mistress. To the speaker, they are proof of their relationship. In the first stanza, she describes her mistress's throat as "cool" and "white," in contrast to the warmth of the speaker, which heats the pearls and improves their luster, preparing them to be worn later by the mistress.
The speaker imagines her mistress spending her day in the Yellow Room, contemplating which dress to wear. She contemplates silk and taffeta and fans herself while the maid "works willingly." Her focus on the fabric contrasts with the speaker's passion for her mistress, but the speaker does not appear to pick up on this discrepancy. "Slack on my neck, her rope," the speaker says. The necklace suddenly seems more like a harness, a symbol of the mistress's power. By describing the necklace as "slack," the speaker implies that it has the potential to tighten; this potential parallels the potential sexual tension between the two women.
This second stanza throws the disparity between the characters' social classes into relief. The mistress worries over her choice of luxurious fabric for the evening, while the maid warms the pearls and works diligently. Duffy also divides the two characters by temperature. The maid is warm, while the mistress is described as "cool," and she fans herself to stay so.
In the next stanza, the maid is in her bed in the attic. Again the poem highlights her low station, yet the character takes no notice of it, dreaming of her mistress. She imagines that the pearls retained some of her own smell, which confuses the men who dance with her mistress. In this way, she has some claim over her mistress that her suitors can sense, even if they are not sure what it is. The "faint persistent scent" of the speaker is contrasted with her mistress's perfume.
Here she describes the necklace as "milky stones." The word "milky" links them implicitly to femininity; the word "stones" feels heftier than "pearls" and implies their solidity and tangibility. Because the necklace is the main piece of tangible evidence of her relationship, the speaker understandably clings to their image, exaggerating their size and their significance.
In the next stanza the speaker is with her mistress again, dusting her bare shoulders with a rabbit foot. A rabbit foot is often used as a talisman for good luck, but here it acts more as an extra limb for the maid, through which she is able to make physical contact with her mistress. The soft material of the rabbit's foot evokes the earlier mentions of taffeta and silk, yet it also subverts it. The rabbit foot, being an object of superstition, feels coarse; it is to the maid what silk and taffeta are to the mistress. Yet the mistress does not object to its touch, instead blushing. This moment is the first in the poem to firmly suggest that the intimacy between the two women is not one-sided. Yet the speaker compares the blush to a sigh, an interesting choice because a sigh would be a more explicit sign of the mistress's desire, while a blush is uncontrollable. Whether the mistress feels the sexual tension between herself and her maid or merely responds with pleasure to the touch of the rabbit's foot is unclear.
The speaker then looks at herself in the mirror, where she sees her "red lips part as though I want to speak." The red lips parting are clearly sexual, and by including "as though I want to speak," the speaker makes it clear her lips are parting for different reasons. This moment also emphasizes the ways in which the characters are and are not allowed to express themselves; the speaker's silence is more charged than her words could be, because the behavioral restrictions of the Victorian era would not allow these women to express their sexual desire for each other.
The next stanza follows the mistress home in the speaker's imagination. The stanza begins with the simple, fragmented sentence, "Full moon." The moon is reminiscent of the pearls, and by hovering over the mistress's head, it suggests the way the speaker's desire intrudes her visions of her mistress. The mistress arrives home in her carriage, unaccompanied by the men with whom she danced at the ball. She undresses and gets into bed naked. The speaker describes "her slim hand reaching/for the case," but not how she puts the necklace away. The speaker focuses more strongly on her mistress's body and the pearls' continued presence.
The speaker also says that her mistress gets into bed naked "the way/she always does..." Here the poem suggests that the women have been intimate. This moment is also a good example of the way enjambment in this poem sometimes feels forced into its shape, with sentences cut awkwardly by line breaks. In the first stanza, for example, Duffy breaks sentences at places that seem unnatural, saying, "My mistress/bids me wear them, warm them, until evening," and, "At six, I place them/round her cool, white throat." This may be a nod to behavioral standards of the Victorian era, which would not allow for a relationship between two women, nor a relationship crossing classes; the women are pushed to adhere, just as this poem is pushed into its form.
The concluding stanza focuses once again on the necklace, how her warmth is dissipating from it into her mistress's room. She says, "All night I feel their absence and I burn." This final sentence suggests that the necklace works both to keep her cool and to keep her mistress warm. Their relationship is symbiotic, or at least the speaker perceives it as so.
This poem is split into six stanzas with four lines each. Other than that, the poem does not follow a traditional structure. There is no rhyme scheme and no set meter.