The speech known as Jaques' "The Seven Ages of Man Speech," at the end of Act 2, Scene 7, contains many different metaphors as well as similes. For starters, the speech itself is an extended metaphor describing life. Jaques likens life to a stage in a theater and people living life to the actors in a play. What he is essentially saying is that life is an arbitrary pattern of beginnings, endings, trials, and hardships. His speech is also given in response to Duke Senrio's comment after encountering starving Orlando and hearing of his near-to-death faithful servant; Duke Senior comments on the fact that no one in life is exempt from unhappiness and "woe," and Duke Senior is the one who starts the "life is a stage metaphor" (II.vii.136-139). Therefore, Duke Senior and Jaques are arguing that life is arbitrary and full of hardships. The metaphor likening life to a stage and people to actors works because we can clearly see how living life is like giving a performance that is meaningless beyond the moment. Within the extended metaphor likening life to a performance there are also a few other smaller metaphors. Below are a couple of ideas to help get you started.
Beyond likening life to a performance, he also likens various phases of life to various acts in a play, which is a second metaphor. Also, within this second metaphor is a third interesting metaphor likening the human phase middle age to a judge, as we see in the passage:
And then the justice,
In fair round belly with good capon lined,
With eyes severe and beard of formal cut,
Full of wise saws and modern instances;
And so he plays his part. (153-57)
In this passage, "justice" is another word for judge. Essentially, in this passage, he is likening a man in his middle ages to a judge, someone wise enough and experienced enough to correctly interpret and judge situations. However, this wise judge is also not without his corruption. In the line, "In fair round belly with good capon lined," the word "capon" refers to highly fattened male chickens; capons were especially known to be "used to bribe judges" (154; Shakespeare Navigators). Hence, in this one line, he is referring to the middle-aged man's past corrupt ways. Jaques also describes the middle-aged man as being "[f]ull of wise saws," meaning wise sayings, and "modern instances," which refers to contemporary situations, meaning that the middle-aged man is up-to-date on all that's going on in his world, adding to his wisdom. Hence, we see that Jaques is using this third metaphor to describe a man who has lived a while, is now in his middle ages, and has experienced life, including all of life's corruptions, making him wise. This is a useful metaphor for describing a middle-aged person because we certainly do, hopefully, increase in wisdom as we reach that age.