Your Avatar represents your current strengths, and also has traits that you strive for. While your Avatar is a fun way to personalize your Dashboard, it's much more than that - when you are feeling unmotivated, having a difficult time, or you 'don't feel like you have what it takes', you can 'transform' yourself into your Avatar. 'What would my Avatar do?' (AKA, 'what would the person I am striving to become do in this situation'?)
Your Avatar will be designed by a professional artist - this is the description that I pass on to them. I may add some embellishments or additional descriptors, and of course the artist will use creative liberty to fill in any gaps that you leave out.