I don't think there's improvements really on the SSC site piece, I really think it's a difference in the clothes. If you look at the SSC pics, the tshirt collar comes higher up, the jacket lapels are flapping a bit because it's higher, I think the clothes are just pulled down more on the in hand shots.
I see nothing to suggest alternate pieces. I've never seen Sideshow post production images that weren't a production piece. What's in the box is the same thing we're getting, just will vary in how the clothes are futzed. Like I said, a little padding or whatever to broaden/beef up the shoulders and this should look better.