Lady Macbeth uses the imperative to command Macbeth to 'look' and even to 'be' as though it is as if she controls him like a puppet, and this dangerous female power would be particularly disturbing for Shakespeare’s audience. The imagery of the ‘serpent’ evokes the devil, linking Lady Macbeth to supernatural evil and manipulation, juxtaposed with the ‘innocent flower’ which they pretend to be, showing the theme of appearances and reality.