lol, well I don't mean disrespect or anything. But when someone requests something from someone and the designer makes the image for that person but doesn't use it, but requests another a designer could feel he is being used or his time was wasted. So to me in order to get a 2nd request you have to first use the first requested image.
Now if the person added the new sig to his signature box, and would like another I am open to doing that.