A team member takes a suggestion, immediately two players sit in chairs next to each other and begin to talk as if they were being interviewed in a documentary film. After a short period, the two are tagged out, and another couple sit and speak on the suggestion. The second pair is tagged out and a third pair comes in. Then the first pair tags in and speaks for a shorter period of time followed by the second and third. Then one last time all the pairs go in order faster than any of the previous times. After the third pair goes up a third time, the whole thing is given a sweep edit and the show begins.
It's important for players to offer numerous of gifts to each other in this opening, avoiding excessive dialogue or plot, as this is just an opening, and not a scene.
Details about a situation, actions, or world that the pairs have created can be pulled from the opening, or even potentially strong characters that the audience seems to respond to. It's important to avoid playing game in this opening as it makes it harder for your teammates to try and play out the game further after the opening.
I learned this from Billy Merrit he emphasized that each pair's interview should start about one thing, and then evolve into something different. He got this idea from watching documentary films like Sherman's March, where the filmmaker went out to make a movie tracing General William Tecumseh Sherman's march through Georgia and the Carolinas but instead ended up focusing on his love life.
There are many variations of the documentary opening. One more common variation is that the pairs do not necessarily come back. Instead of repeating pairs, new pairs come out until the opening is edited.