In "A Midsummer Night's Dream" by Shakespeare, how is the play within a play a parody of dramatic traditions?

The play within a play, presented by the workmen in celebration of Theseus and Hippolyta's wedding, pokes fun at dramatic traditions in a few ways. Shakespeare appears to be milking the most comedy out of the melodrama the actors employ to perform their roles, making the selected play, a tragedy, an irony.

Shakespeare may have added the play within a play as a way to affirm Elizabethan notions about actors at the time. For example,...

The play within a play, presented by the workmen in celebration of Theseus and Hippolyta's wedding, pokes fun at dramatic traditions in a few ways. Shakespeare appears to be milking the most comedy out of the melodrama the actors employ to perform their roles, making the selected play, a tragedy, an irony.

Shakespeare may have added the play within a play as a way to affirm Elizabethan notions about actors at the time. For example, Bottom is earnest yet dimwitted; Quince is even-tempered, yet suffers at the hands of an unruly cast. Both characters would serve as a ribald punchline for audiences that thought of actors as vain and dull in their offstage lives. 

Through the play within a play convention, Shakespeare also could have been answering to those critics who felt free to demean his work, but had no understanding of sound dramatic structure.