People are confused by symbols if they have too many or too few details. They will recognize UI elements which are somewhere in the middle.

I like this especially when we narrow our focus on game UI design. Games have a tendency to error in the direction of being too realistic. Look at those muddy icons in MMO hot bars. While Mathis points aren’t exactly ground breaking it’s a good solid reminder for us UI designers everywhere.  Read it, understand it, and apply it.

…also he channels Scott McCloud’s Understanding Comics which is a must read for anyone and everyone involved in any level of artistic pursuits.