Two Ghibli created shorts about the happenings in a fictional animation studio, presumably based to some extent on their own.

The first was aired during a TV special about Ghibli, the second shown in theatres alongside 'The Cat Returns'. Note that the animation studio in these shorts is not spelled ジブリ (hepburn: 'jiburi'), but ギブリ (hepburn: 'giburi'), so pronounced with the hard 'gi' of 'give' rather than the 'ji' of 'jigsaw' used for Ghibli. (Source: AniDB)