If the subject is the content of a biodoc, then aspects of their identity can inform the documentary’s form.

A recent example: the fact that Martha Stewart is the only talking-head that actually appears on screen in Martha. 

There are contemporary interviews with the usual coterie of commentators, who provide correctives on how she tries to spin the story of her life. 

But they’re never shown.

Instead, Martha’s present-day sit-down is the sole talking-head granted the privilege of the camera. The other participants may alter the verbal narrative, but they’re forbidden from affecting the visuals of the documentary. 

And Martha Stewart singlehandedly dominating the appearance of a Martha Stewart documentary is very Martha Stewart. 

That’s content and form, baby.