The speaker opens with a reference to the "secret" of her own beauty, claiming that "pretty women" want to understand how the speaker can be so alluring without being considered conventionally attractive. The speaker explains that she may not meet social definitions of "cute" and that she doesn't fit the expected mold of what an attractive woman is supposed to look like.
She specifically calls out the fashion industry, making note of the fact that she doesn't have the tall, skinny build of a model. On a formal level, note how this line is the longest in the poem—a visual refutation of the idea that the speaker must shrink herself down to fit the fashion world's ideal of feminine beauty.
Notably, the speaker claims that when she explains her secret to these women, they believe she is "telling lies." This suggests that rigid definitions of beauty are so ingrained in women that they struggle to believe any alternative perspective, even when it's coming from another woman. By touching on women's visceral rejection of the truth, the speaker subtly reveals the profound psychological impact that cultural conditioning has on body image and self-perception.
These "pretty women" have internalized the attitudes of a society that glorifies the supermodel physique as the ideal to such an extent that they are blinded to the truth. In this sense, the speaker attempts to refute and deconstruct the harmful models of beauty that warp women's understanding of the world and themselves.
The first four lines of the poem feature intense alliteration and consonance of the /w/, /t/, /s/, /l/, and hard /k/ sounds:
Pretty women wonder where my secret lies.
I’m not cute or built to suit a fashion model’s size
But when I start to tell them,
They think I’m telling lies.
There's also assonance here, such as can be seen in the internal rhyme between "cute" and "suit." This opening chunk features a clear AABA rhyme scheme as well, with "lies" in line 1 rhyming perfectly with "size" in line 2 and "lies" again in line 4. The first four lines of the poem are thus intensely musical, suggesting the beauty and confidence of the speaker's voice itself.
Though the poem overall is written in free verse, these opening lines are very steady in their meter. The first two lines are clearly trochaic (meaning they follow a stressed-unstressed beat pattern), while lines 3 and 4 are iambic (unstressed-stressed):
Pretty | women | wonder | where my | secret | lies.
I’m not | cute or | built to | suit a | fashion | model’s | size
But when | I start | to tell | them,
They think | I’m tel- | ling lies.
(Note that, in line 2, "I'm not" could also be scanned differently; it's ambiguous). Overall, this adds a bouncy, steady rhythm to the poem's opening—one that will noticeably be shaken up in the second part of the stanza when the speaker begins talking about her unique appeal.