That's definitely part of it. They're hemmed so short it's rough to distinguish between a higher rise and Urkel.
I realize I'm on the wrong side of history but I think a thin guy is better off with a lower rise unless he's wearing a vest.
Well, seriously, I don't think he's actually wearing them that high. I think the low button stance is contributing to the Urkel effect, but the pants seem to be at his waist, not above his ribcage.
And I believe thin people actually look better than phat dudes in a high rise. A bigger guy with pants hiked up high will look even wider because of the horizontal to vertical dimension ratio of his apparent upper body.. a thin man will look more proportioned. Unless he's got really long legs.