A woman accepting obviously flawed reasoning for her punishment actually IS sexy to me. What shows more submission than a female throwing her (correct) conclusions out the window and saying "I will accept his way"?
That's just part of the game, as far as I'm concerned. For me, you can boil every action down to this exchange.
DOM: "What is 2+2?"
SUB: "4."
DOM: "From now on, 2+2 is 5."
SUB: "But 2+2 isn't 5..."
DOM: "Heed my words. From now on, 2+2 is 5."
SUB: "Yes, master."
DOM: "Good. Now, what is 2+2?"
SUB: "5!"
DOM: "Wrong. You stupid slut. The calculator shows it is 4. Now I must punish you."
I see no problem with this. The sub says that 2+2 is 5 because she *wants* to be punished. She's throwing away what she knows because that's what her master wishes, and because she wants to feel his firm hand. And that's submission.
- FS
PS: Here's the above conversation with the actual words of your example added in.
DOM: "How do you plan to dress?"
SUB: "Tastefully- subtly. Making the best use of all of my features..."
DOM: "That will never do. I want you to wear this miniskirt, with no panties. Slit it up the side. And no bra."
SUB: "But...that's not a proper way for me to dress in public!"
DOM: "Just do it. I desire it of you."
SUB (hesitant): "Very well, master."
(later)
DOM: "Have you dressed as I instructed?"
SUB: "Yes, master- a short skirt, no bra, no underwear..."
DOM: "What an indecent whore you are! You should be ashamed of yourself. I'm going to slap you around for this!"