How was the "play within the play" reflective of the main plot, given its absurdity?

Shakespeare uses the play within a play to prove a point about theater. His purpose in creating this parallel is to show the way in which this play could have been a tragedy rather than a comedy. The Pyramus and Thisbe play parallels the actual action of the lovers. Pyramus and Thisbe run away, and a lion (one of the monsters in the forest) then emerges and seizes Thisbe's cloak. When Pyramus sees the bloody cloak, he assumes the worst and rashly commits suicide. This ending could easily have been repreated in the ending of A Midsummer Night's Dream.