I find it kinda refreshing that Litten has this "I don't give a d@mn" look to it. Almost every Starter we've ever gotten has always appeared to happy-go-lucky excited. But then we have Litten who seems like he could care less whether you were the very best like no one ever was or lost every match possible. It just wants it's catnip and to be left the heck alone.
Also, I know this has been said WAY too many times but did Gamefreak seriously not see the connection between naming him/her Litten when it's ability is Blaze? It's like they're asking for it to become the 4/20 mascot. I swear, if it's evolution has anything to do with smoke, I'm convinced we're getting troll'd.
Snivy did have the smug look, which was also refreshing to see. Smug and prideful, quite fitting for it really. I do like Litten having that type of expression, also having that opposing personality of being passionate but also hiding the emotions it has. Really nice touch.