This is a great example of a high confidence female stance contrasting with her low confidence male companion.
Notice the feet (legs) of Tara Palmer-Tomkinson, a London Socialite, are moderately apart - which projects greater confidence, while her unknown guy's feet (legs) are together. Generals stand with their feet apart. Enlisted men stand with their feet together. Tara's shoulders are relaxed and spread back - his shoulders are hunched forward and elevated. Her neck is extended and proud. Mr. unknown's neck is foreshortened and he reminds us a bit of a turtle. Ms. Palmer-Tomkinson's body and her face are pointed more towards us - his body is pointed away. Her eyes are open and alert - his eyes look tired. Her face shows a mild social smile - his mouth is more neutral. While Tara is holding her purse, his hand - except for his thumb - is in his pocket. While he could have displayed even less confidence if his whole hand were tucked in his pocket, in this setting even part of his hand is his pocket screams "Don't talk to me - I am not confident!"