The Birth of Venus

The Birth of Venus (Italian: Nascita di Venere [ˈnaʃʃita di ˈvɛːnere]) is a painting by Sandro Botticelli generally thought to have been made in the mid 1480s. It has long been suggested that Botticelli was commissioned to paint the work by the Medici family of Florence, Italy, specifically by Lorenzo di Pierfrancesco de' Medici (1463-1503) under the influence of his cousin Lorenzo de' Medici, a major patron of Botticelli. However, no originating documents associated with the painting survive,
and its first linkage with the Medici family is not recorded until several decades after the supposed date of its creation, namely in the 1550 edition of Vasari's Lives. It depicts the goddess Venus, having emerged from the sea as an adult woman, arriving at the shore (which is related to the Venus Anadyomene motif). The painting is in the collection of the Uffizi Gallery in Florence.
Classical inspiration
Capitoline Venus, derived from Aphrodite of Cnidus
Venus de' Medici
The pose of Botticelli's Venus is reminiscent of the Venus de' Medici, a marble sculpture from classical antiquity in the Medici collection which Botticelli had opportunity to study. The figure of Venus is also similar to Praxiteles' sculpture of Aphrodite. In this version of her birth she rises from the sea already a grown woman.

Since classical antiquity, the sea shell has been a metaphor for a woman's vulva.
Style
Botticelli's art was never fully committed to naturalism; in comparison to his contemporary Domenico Ghirlandaio, Botticelli seldom gave weight and volume to his figures and rarely used a deep perspectival space. In the Birth of Venus, Venus' body is anatomically improbable, with elongated neck and torso. Her pose is impossible: although she stands in a classical contrapposto stance, her weight is shifted too far over the left leg for the pose to be held. Moreover, her positioning on the edge of the scallop shell (which cannot be identified as real), would certainly cause it to tip over. The bodies and poses of the winds to the left are even harder to figure out. The background is summary, and the figures cast no shadows. It is clear that this is a fantasy image.