This is what I understand. I hope this helps.

The act of giving the jewel to Lady Moudle is just a means to an end; that is to find the one who crafted the jewel. Joanne thought of the idea that "finding the crafter on their own is too much of a hassle, why not shape the public opinion and let the nobles do the work." With the gift together with its heartwarming story, noble families, who are sure that the jewel will be going to be a trend, are now eager to find who crafted it because they must get their hands on that jewel to keep up with the social trend. By that, the crafter will now be forced to come into the spotlight. Goal Achieved!