His virtuosic new special, “Inside” (on Netflix), pushes this trend further, so far that it feels as if he has created something entirely new and unlikely, both sweepingly cinematic and claustrophobically intimate, a Zeitgeist-chasing musical comedy made alone to an audience of no one. It’s a feat, the work of a gifted experimentalist whose craft has caught up to his talent. And while it’s an ominous portrait of the isolation of the pandemic, there’s hope in its existence: Written, designed and shot by Burnham over the last year inside a single room, it illustrates that there’s no greater inspiration than limitations.