This is such a meta episode, the fact that the season focuses on a TV show it leads audiences to forget we are actually watching a tv show. Philbert shares so many parallels with Bojack Horseman, from the setting right down to the fact that the main character is the name of the show. Every cynical thing Diane says to Bojack in this episode can be applied to us viewers of Bojack Horseman, it's almost as if Bob-Waksberg is literally communicating with the audience via Diane and Flip (especially when flip says how clever 'Philbert' is and if you don't understand it your stupid, a little meta joke about Bojack audience). This is a very real and meta discussion about the effect/influence of Bojack Horseman on us the audience.
Furthermore by depicting Bojack's opoid addiction in such a painfully realistic way to again blurs the boundary between what is Bojack, and what is a viewer of the show. By making his character so real and relevant to a current crisis in the USA, with the backdrop of 'Philbert' it leads to a hyperreal season where the discussion points are intrinsically linked to the audience watching Bojack Horseman. Postmodernism at it's most subtle and finest.
EDIT: The fact that Bojack himself in this season struggles between what is real and not because of his addiction, further reinforces the blurred boundaries that this episode depicts. Bojack is so real, he also struggles with what is a TV show and what is 'real' (for him as a character on a TV show), much like the audience watching the show.
Insane writing, insane episode, insane season, insane TV show.
EDIT: The fact that Bojack himself in this season struggles between what is real and not because of his addiction, further reinforces the blurred boundaries that this episode depicts. Bojack is so real, he also struggles with what is a TV show and what is 'real' (for him as a character on a TV show), much like the audience watching the show.
Insane writing, insane episode, insane season, insane TV show.