We might write about anything. Robert Frost was inspired by the snowy woods. Van Gogh painted old shoes and he painted them with feeling and did it several times. The work doesn't tell us so much about the shoes or the woods as it tells us about the poet or the painter. We get a clear view of how their mind works. In a way each good work of art becomes autobiographical.
I reread a book by Natalie Goldberg recently entitled LIVING COLOR. In it she tells of how she thought Picasso was a "genius creator" until she read a biography and decided the man was cruel and she no longer cared for his work. Natalie might have taken a hint from the way Picasso painted women. The way he twisted their faces and moved features around. Using distortion and sacrificing realism for artistic expression. The man is all there in his paintings.