Both are authentic in their own way, while one may be more detailed than the other, both are showing their authentic selves. Art shows who the person is on the outside, but sometimes can have a more deeper meaning about personal life or what experiences they went through. You see it all the time. As for autobiographies, you are hearing the persons story through powerful words. You know who they really are as a person or what life was like or what happened at a certain event that they went through because I mean, they told you. I feel like after this explanation it’s for you to decide which is more authentic, but this seems like a more opinionated response that has no wrong or right answers. Hope that helps some.