The scene is helped by a set-up.
In the first season, Gervais plays a character, Andy Millman, who's an extra in the British film and TV industry, but with greater hopes, among them trying to sell a series he's written. In the second season, the show has been sold, When the Whistle Blows, about workers at a factory, but he's very unhappy how the BBC has dumbed it down, and his co-starring character is just a bumbler with a stilly catchphrase ("Are you having a laugh?!") that has caught on.
In this scene, he's gone to a bar with some friends, including his clueless agent played by Stephen Merchant. Gervais is feeling a bit down, somewhat wanting to be recognized and appreciated, but mostly wanting to be ignored. They pay 60 pounds to sit in the V.I.P.section, in part because he crosses paths with his snarky nemesis and wants to impress the guy, but mainly he's feeling shy about it all.
Then they spot David Bowie there and...
Well, here it is --