Vermeer's genre scenes have a remarkable sense of privacy. The viewer often feels as though he has been allowed to share discreetly in moments of people's lives unfolding in the intimacy of their homes. Here, Vermeer provides a quiet space in the corner of a room behind a rug-draped table for the young woman to read her letter. Light from the open window glows radiantly on her head and shoulders as she intently follows the letter's words. Seen in strict profile, she is unaware that her emotional response is dimly reflected in the windowpanes before her.
This painting has an immediacy that stems from Vermeer's increased interest in naturalistic, and even illusionistic, effects. Not only does he suggest the translucent and reflective qualities of glass, but also the sheen of the woman's lemon yellow sleeves, and the nap of the wool rug, which he accents with colored highlights. The most remarkable illusionistic element, however, is the large, yellowish-green curtain hanging from a rod stretching across the painting. Partly because light falls on its front surface, the curtain seems to belong to the viewer's space, as though it has been pulled aside to reveal this intimate moment in the young woman's life.