Final answer:
In Act III, Scene II of 'Hamlet,' Hamlet accuses Guildenstern of trying to play him like a musician plays a pipe, highlighting his refusal to be manipulated.
Step-by-step explanation:
In William Shakespeare's Hamlet, the metaphorical comparison that Hamlet makes between Guildenstern and a player's pipe occurs in Act III, Scene II when Hamlet accuses Guildenstern of trying to play him like a musical instrument.
Hamlet is exasperated with Guildenstern's attempt to manipulate him and reveals this through the metaphor, suggesting that Guildenstern is attempting to make Hamlet respond to his probing questions and subtle machinations as easily as a musician produces music from a pipe. This comparison emphasizes Hamlet's awareness of Guildenstern's intentions and his own refusal to be controlled or played.