Marcette's poem is a defiant answer to someone who mocks the speaker's appearance. It opens with a stark command, "Flay off my false skin," and then admits that the speaker likes to conceal and highlight her face, a choice the other person dismisses or won't listen to. A small, bitter aside, "It isn't like anyone, especially me, would care," hints at hurt underneath the bravado.
From there the tone hardens. The repeated "My confidence to..." builds like a drumbeat, moving from simply enjoying her appearance to rebelling just by existing. The word "cytherean," a nod to Venus and beauty, shows she claims glamour on her own terms. The final image is the sharpest: she corrects herself from "thorn" to "spear," growing bigger and more dangerous in the side of her critic.
The mood is angry, proud and fierce. The speaker turns an insult into fuel and promises that being herself is the strongest form of resistance.