Yeah, looks similar to my 3 1/2 yo too , expression-wise (ofcourse, he's a he.)
Heck, even the DS 7 is looking that way alot (I thought THOSE attitudes had passed - turns out they come back!! Does your older boy still have "moods"?)
Is you 3 1/2 yo a Chrsitmas (or nearby...) baby? - mine was born the day after Xmas (they took him away to wash/weigh him right after he was born and brought him back to me in a xmas STOCKING!!

I was so out of it I was kind of confused about why they were bring me a xtocking at first!) - poor thing doomed to an anticlimatic b-day.