Ironically, the Cod piece was to overcome the shortfalls, bigger Cod piece, bigger fish. Poor Maidens, fooled by such deceit, when a tight set of jeans would have achieved the same effect. As far as the (2nd) picture below, I can see any advantage to having your jeans pulled down half way down your butt. Of course, I am not of that persuasion, so maybe their thinking, "I'm half way there"?
As far as floundering Cod pieces, considering the time they were used, I wonder if someone ever asked, "Mind if I borrow your Cod piece tonight, I've got a hot date, and my I left mine in Flanders", where floundering Cod pieces always end up. Oh the humanity, or lack of it.
This pic ( 1st pic below) is from Wikipedia, so yes, I again have broken my own rule

, but really, who did these guys think they were kidding? That thing would have scared the bejesus out of any of the woman I ever knew. Bawdy Brits, and most other nobility of that era!