Generally when people call someone a poser it isn't a good thing.  However, I can't think of a better term to describe my daughter, though the meaning is a tad different than some will think.  I mean she HAS to pose for a picture.  She can't just let you get a candid shot.  Unless I can get one while she isn't aware, but that is hard.  See here are some of her "poses."

This is the closest I got to "normal."  The smile on the other hand is far from natural.  It is her "cheese."

Even when asked to stand (STAND!) by her brother she poses.

One day she look back on these and laugh.  In the meantime, I'll just keep trying for a "natural" picture.  But right now that is her, so what can I say?