In Macbeth, Lady Macbeth conveys an important message about appearances versus reality. She tells Macbeth that his face acts like a book, revealing his thoughts and emotions to those around him. This metaphor emphasizes the idea that one should conceal their true feelings and intentions, allowing others to see only what is presented on the surface. By suggesting he should “look like the innocent flower,” Lady Macbeth encourages him to mask his ambition and treachery behind a façade of charm and hospitality.

Furthermore, Lady Macbeth underscores the need for deception in a world where ambition and desire can lead to dangerous outcomes. The contrast between the "innocent flower" and the "serpent under't" illustrates this duality, highlighting the theme of betrayal that runs throughout the play. Ultimately, Lady Macbeth's counsel serves as a crucial turning point for Macbeth, as he grapples with the moral implications of his ambitions and the lengths to which he must go to achieve power.