What metaphors does Shakespeare use to convey Macbeth's attitude toward life after Lady Macbeth's death?

This is Macbeth's famous depressing speech,

"Life's but a walking shadow, a poor player. That struts and frets his hour upon the stage. And then is heard no more. It is a tale. Told by an idiot, full of sound and signifying nothing."

Here he compares life to a pathetic actor doing his one performance on stage and disappearing forever, his life a useless folly.