I’m in absolute adoration of this character.
He has a very specific body language, holds himself in a purposeful manner that lends itself well to the imagining of how he might move. In some ways, it actually goes contrary to the common fandom representation of him as someone constantly rigid and at attention. Though there are certainly aspects of that to his character (as we can see when he stands at the witness stand), Miles Edgeworth is actually primarily very relaxed.
His posture is actually more lax than that of his courtroom rival, who looks confident, hand on his hip, or finger pointing at the viewer, always CONFIDENT. And it is confidence, true, earnest, and incredibly expressive (and a bit sassy, what with the hand on his hip and that cocky grin). It is far different than Miles.
Miles is at ease his stance almost casual, with his hands in his pockets. It is something entirely affected, a way of acting that is driven by projecting a certain image. Miles Edgeworth, more than Phoenix Wright, is a showman who is in perfect control of his trials … And his appearance and how people receive him. He looks at the viewer from down his nose with a sidelong and intense glance,brow furrowed, frowning slightly …
It is a look that is made all the more intimidating by the fact that he IS so relaxed. It doesn’t feel forced at all. Despite that, his back is still straight and he is meticulously dressed, ever button in place (as opposed to Phoenix, where sometimes you see buttons not done up properly, etc.), making him feel very put together, but never in a forced way.
Whereas it is easy to imagine Phoenix moving with an easy stride, perhaps tripping over his feet sometimes but always recovering, with Miles one imagines a purposed but effortless gait, someone who never trips because he is perfectly aware of the measure of his steps. It is the walk of a predator, someone who feels no threat from others and assesses you with a cold glare while remaining utterly relaxed.
It is easy to understand why he has the reputation he does in universe when you think in those terms.