Overall I liked the episode quite a bit. One of the charms of the series for me is how small conflicts are woven into a bigger narrative. Sure, it's just a ball dress for a provincial noble, but now Mia got one less barrier between herself and a happy ending. (There are further implications later on, but I'm not spoiling it.)
And while Mia was 90% lucky, this episode shows the other 10%: in the earlier loop, she didn't have the chance to make her few skills (ball dancing for example) work in her favour. Or the fact that she actually considered the PoV of the four nobles, instead of ideologically dismissing it.
I think my favorite thing about this show is that they didn't go full "I'm gonna change my ways and be nice to everyone to fix my future" like a lot of shows would. She's still the same selfish character (for the most part) and isn't doing her good deeds out of any sense of altruism. Rather she's trying to help herself, and in the process is righting wrongs that she still is mostly unaware of.