Hmm interesting. I see the one on the left as more extraverted and sharp. The one on the right as more subdued in a sense though still extraverted. I can't really say anything about their inner stuff.
One on left is more of a forced extroverted and I can see what you describe as sharp. It seems more forced extroverted and a more forced expression. Right seems more natural and yes, due to that it is alot more subdued and more of a this is me. Left seems more like I have to almost change my feelings, and then portray that out into the world in the correct expression to get the point across. Which is what causes the more exaggerated extraversion as opposed to the more natural subdued.