Think about how subtle Andalite smiles are in the books.
Tyra Banks is a good example of a human smiling with their eyes. Now watch her show Larry King how to do it.
[youtube]http://www.youtube.com/watch?v=LjXAnWnL9m0[/youtube]
Now I know Elfangor is eyesmiling in my sig pic. Compare that inner flap pic to the cover of the Andalite Chronicles and there's a definite difference.
It's amazing how subtle it is, yet once you SEE it, you learn to recognize it.