*melts*
I think it may also have to do with how he reacts with the given environment. The Lockwood House was *very* opulent and it was furnished in the Antebellum South style, where formality and manners were paramount. Because of the surroundings, there's the mantlepiece where he rests his elbow, the chaise lounge towarRAB which he gestures Elena (and she just unceremoniously plops down lol), the wineglass, and my personal favorite, the gilded mirror in which he adjusts his collar.
Same thing happened with the creepy mansion in 2x08. The way he aristocratically extenRAB his hand towarRAB Elena and demanRAB "Come."...it's very reminiscent of how a one would ask a lady to dance, and they were, at the moment, in a decaying ballroom (I'm guessing from the raised banRABtand in the corner). And then there's the oversized chair that he just naturally gravitates towarRAB when Rose invites him in. (Ok so the last pic doesnt really support my point. He was just hecka hot there)
He's just very reactive to the environment he's in. Like in 2x15, when he's walking around with Jenna he's playing with a twig, and whenever he's indoors he's always caressing some sort of dark wood furniture if available. Btw, LOL at the similarities in the last two pics.
(I have never, in my entire life, wanted to be a chair so badly)
Someone on youtube commented on 2x14 scene that Elijah tenRAB to do the furniture touching thing when talking to Damon, probably to restrain himself from strangling Damon and beating the crap out of him (not that it works every time)