A huge percentage of the time professional photographers pose their subjects in body language which is off the emotional-context mark - way off. They may be good at lighting, knowing the best angle, picking the right filter or lens - but relatively few professional photographers have any significant amount of nonverbal knowledge. The same is true for advertising professionals. The wrong expressions and body language are often used despite teams of people, months of effort and millions or even tens of millions of dollars spent (or more).
If Annie Leibovitz is trying to capture a successfully transitioning Caitlyn Jenner - from a body language perspective - she hits the mark. Of course a magazine cover presents a very different and artificial scenario vs. interpreting body language in real-time and real-life, however Jenner's arms behind her back with her hands clasped - projects a strength, confidence and alpha emotional tone - which is certainly in her character. It also sends signals of significant openness - and who in World history has made a more open transition? While of course currently there are other important reasons for such a configuration, by keeping her legs tightly crossed - Jenner still transmits femininity (as do her bare shoulders).
By rotating Caitlyn's head to one side (projecting coyness), tilting her head/neck downwards - makes it so that in order to have eye contact with the camera, she must look up - which necessitates more widely open eyes (This is true with her right eye, while Jenner's droopy left lid [ptosis] gives the secondary effect of "bedroom eyes" here - adding to the sexuality). The combination of Jenner's head & neck tilted down - yet upwardly gazing with Leibovitz's slightly downward camera angle, also projects a "come hither" look - which is often emulated in every day flirting and romance.
The one suggestion I would make regarding this specific photo, is to not have Kaitlyn's back a corner. This component gives the feeling of her being bad, trapped or "cornered" - and is a visual metaphor suggesting a decision that is punishment or forced, rather one of free will - which of course is an important sentiment and distinction.
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