Philostrate is Duke Theseus's party planner. His official title is "Master of the Revels," which happened to be a court appointed position in Shakespeare's day. Basically, the Master of the Revels organized courtly entertainments and also determined which play could be performed at court and on public stages. Because plays weren't supposed to be rebellious or offensive to the monarch, this job also entailed a fair amount of censorship.
In the play, Philostrate doesn't think the Mechanical's play is worthy of a court performance in honor of Theseus's wedding. When Theseus demands to see it, Philostrate replies like a snob: "No, my noble lord; / It is not for you: I have heard it over, / And it is nothing, nothing in the world;" (5.1.4). Is Shakespeare bagging on the uptight masters of revels who determined which plays could be performed in London? You decide.