A lot of people say I based Mark on me. Not so. Man, I wish I looked like that, and that my hair worked that way.
When I originally designed him, he was blonde. In his original incarnation, it made him look too much like Mr. Incredible, so the hair had to go. Black was out, as that was too Superman. I wasn't in favor of red, so what was left was brown. There weren't a lot of brown haired heroes anyway when I was growing up, Green Lantern being the notable 
exception. Yeah, there was Peter Parker and Cyclops, but I wasn't into Marvel back then.
Mark does act like me, though. I'm the main model for most of the characters. When I have to think of how someone would stand when they open a door or read a letter, I'm the guy who's the template. In this scene, Mark's working in him home office, so he's dressed casually. I dressed him the way I've been known to dress. Heck, I was actually wearing that outfit when I drew it, because I was trying to nail how an open shirt would hang and fold.
Why he's doing what he's doing in that panel is immaterial. You'll find out in May anyway. But the way he's sitting, grabbing from one stack and tossing away with another hand, I think it looks right. He looks like he's really inhabiting that world. I think it's one of the best things I've drawn in a while. (And, I attribute a lot of my character's better acting to the Drawn to Life series of books collecting the lectures of Walt Stanchfield. If you're an artist, buy 'em both. Now!)
Sometimes the little moments are the toughest, and the most worth it when you get it right.