The mission is very easy. The only thing you have to do after getting to the sculptor is to stand in the given place, strike a pose and hold it for some time (an adequate info will be shown). After this info, you only have to hit (A) at the right moment (you have to hit the green area), and you will strike a perfect pose. It's the same in every city, in which you can have your statue.
You can place the statues in different regions, after discovering a place where you can put it (concrete platforms). You must pay for each, and you'll receive renown points in return.