Rules are simple. Rate the profile avatar of the poster before yours on a scale 1-10.
Judging and rating should be somewhere a long the lines of appeal, relativity, awe factor, humor, or a worthy/unworthy reference. Don't be too personal and biased but be be honest.
Then explain what and why your avatar was worthy of being your profile pic so the next poster has a little fair ground to rate you on.
Be respectful. If you don't like the previous avatar maybe explian why or just state your indifference about the avatar's subject matter. If you like it then let them know why.
My avatar is of Ramza Beoulve from Final Fantasy Tactics. Ramza is one of my favorite protagonists from the Final Fantasy installments. He started out a good-hearted noble with decent intentions but ends up having a robin hood-like mentality, a selfless attitude and altogether a publically unknown hero of the people. Unlike the majority of the Final Fantasy protaganists Ramza, for the most part, never swelled under pressure and has one fitting of an ending for a great game.