That kind of stuff, however, gets covered quite adequately in other areas of the Dojo (particularly the Balance tutorial). So, instead, I'm going to cheat and use this tutorial to discuss stance in the way that animators talk about it.
In animation terms, Stance is the combination of elements that make a character come across well to the audience independent of major bodily animation. The basic goal is to cross the line between a conglomeration of control points held in a particular shape, and a living breathing character who just happens to be standing particularly still.
Throughout, the fight to achieve good stance is the fight to introduce measured imperfection into the character. While people are impressed by perfection in reality, they are impressed precisely because perfection is unbelieveable. "I can't believe it..." they'll say. But, of course, since they are observing something with their own senses, they generally will believe it.
When you create an animation, however, you don't get the same generosity. If you create something that is too perfect, your audience will quickly, and often unconsciously, dismiss it as unbelieveable. If the audience doesn't believe in your character, they will not be moved by the stories you can tell with that character. And that would suck, wouldn't it?
Computers offer many seductive opportunities to make something perfect.
In modelling, it is simple to create geometrically exact spheres and planes,
or perfectly reflective surfaces. Of course, it's worth the effort
to avoid such temptations. The issues that arise in modelling will
also arise in animation, and there also it is worth the effort to avoid
unbelieveable perfection.