Check out our Diddy/Dirty Money section for more posts about Diddy/Dirty Money.
We now know that "I'm Still Here," the documentary of Joaquin Phoenix's move to rap (watch the trailer) was a performance piece, rather than a documentary. But, it does feature Diddy and you can see the two interacting in a clip from the film below.

Diddy asks if he has the budget for his project, then criticizes Phoenix for not approaching music production in the same manner that you would approach a movie production.