My first response is to the caption which accompanies the image. If this is Marilyn during the filming of The Misfits and the copyright of the image is ascribed to Eve Arnold, then who is the third woman holding the camera? If she is indeed the photographer Eve Arnold herself, then she has set up a second camera somewhere on set and has executed, of all things, a self-portrait with Marilyn. This seems highly unlikely for somebody who is hired to shoot film stills of celebrities at work in the midst of a bustling cinematic production. Another possibility: there is more than one photographer on set observing the interaction between the two women.
The photographer pictured here is also a much older woman who looks "all business" to Marilyn's sexy, playful and elusive self. Each woman has a separate job to do and each dependens on the other to carry it out. This interdependency is what the photograph captures so well. Both women are wearing a soft satiny fabric and –on a formal level- this serves to connect them visually. The way the photographer looks at her model and her gaping mouth speak to her intensity and make her a commanding figure. However, Marilyn does not return her gaze but instead looks aside or perhaps inwards. This diffraction questions the whole balance of power in their equation. The mirror she holds underscores this tension in the photograph.