As the above comment said, he looks edgier. The hand twitching demonstrates the angst pulsing within him and the awkward finger positions look like he's about to fold into a menacing fist. I interpret his hand on his arm as a method of holding back the anger that'll flow through his fist-folded hand at any time. It's the way you interpret it, though my question is how he got his hair like that. How much hairspray do Pokemon characters use?
Hope I helped. :)