Annie Leibovitz’s portrait of Demi Moore for Vanity Fair and Awol Erizku’s portrait of Beyonce are similar in that they both capture famous female celebrities during their pregnancy. There are many differences between these photos but I still think each is successful in communicating their given message. Leibovitz’s portrait is much more dramatic and simple. It forces the viewer to focus mainly on Demi Moore’s emotion and appearance. She is portrayed nude against a neutral background is lit in a Rembrandt style of light at a 4:1 ratio. Her body is in profile while her face is turned in 3/4 view. This allows the viewer to fully engage with Moore’s expression while also highlighting the shapes and curves of her pregnant body. One could say she looks hopeful in the photo, (which any pregnant mother should be.)
This is in stark contrast to Awol Erizku’s portrait of Beyonce. In this photo, Beyonce is clad in lingerie and is posed against a background of colorful flowers. The overall tone is much less dramatic than Lebovitz’s. This is also due to the much softer less contrasting lighting. Beyonce is posed similar to Moore, with her body in profile but her face is fully facing the camera. The flowers that surround Beyonce also portray a different narrative, one highlighting the beauty and nature of birth/pregnancy. While Lebovitz is more concerned with the viewer’s connection to Moore Erizku’s has undertones about the theme of pregnancy.
I would call the lighting style used by Leibovitz in the Demi Moore photo broad light just because her face is in a 3/4 view and the light is falling on the side of her face with the visible ear. And as you point out, one big difference between these two photos is the quality of the light. in Erizku’s image, the light is low contrast while in the photograph of Demi Moore is is higher contrast. 4:1 is a good guess.