Lisa and Elina were trying to appear like nobles while trying to hide the fact that they were princesses, which was why Lisa went with a wig in the first place.
They walked into a clothing store and Ning waited for nearly half an hour before the two princesses could finish choosing 10 sets of clothes, including ones for Reever. Now that he was a prince consort, he needed to stop dressing like a commoner.
Once they were done, they left the area and went to another place at the behest of Elina. It was a jewelry shop with many different kinds of necklaces, rings, earrings, bracelets, etc hanging on the wall in full display. There was a high-ranking Aether user there at all times to protect the store.
Elina seemed to really like the jewelry and started buying a bunch of it. Lisa, after having lived as a peasant for the last 10 or so years, didn't really care much for such materialistic needs.