Camera Shots
Close ups of Sherlock often either have just him in the shot or him blurred out of focus with the other characters – there is a clear barrier between him and the others, and the single focus on him shows a sort of self-importance that is often stereotypical of being upper class (though, generally, the new Sherlock is middle class, bordering upper).
Editing
Fast paced shots help to portray the speed of Sherlock’s deduction, mainly during his explanation of why he thinks Jim is gay. The shots are also blurred to show the focus of the characters as well as the boundaries between them – Sherlock is blurred when others are in close shots with him, probably to represent the ambiguity in people’s opinion of him (a common question raised is whether Sherlock actually cares for people or if he’s a sociopath who does things simply to entertain himself).
Sound
Sherlock is much more vocal about his thoughts than the others – the woman is in denial about her boyfriend being gay, the boyfriend is clearly in denial about himself being gay, and Watson is quiet for the majority of the scene with one of the first things he says being put down by Sherlock.
His accent is also more refined than the other characters – the others are clearly much more casual, where as Sherlock’s speech has a sort of elegance to it that you’d expect from the more upper-boundary of the middle class in society. The accent also helps to portray intelligence, a key focus of the series with Sherlock being, essentially, the most intelligent character in the show (not counting his brother).
Mise en Scene
Sherlock is sitting down – the other characters end up “looking down on him” figuratively by the end of the scene
Sherlock is wearing a suit, as opposed to the work clothes of the woman, the coat of Watson and the t-shirt of Jim.
Sherlock is the central point of the characters – they all face him, and the focus of the conversations are aimed at him as well (the introduction of Jim, the controversy behind Sherlock’s deduction and the counter points by Watson are, obviously, all focused around Sherlock).
Sherlock’s general speech is also very, very different from the others, not just in terms of his accent or formality, but in the way he shows his understanding of the others – ironically, for the most intelligent character in the show, he shows very little understanding of how the others think, another stereotype of the upper-middle class like politicians, who are very detached from the population in terms of understanding what they want.
