What does “smooth as a city” mean?
"Smooth as a city" here is a comparison to the hands of the lady. Just like her hands which are soft and clean because she doesn't have to use them for heavy labor, a city is clean and full of wealthy people who don't have to do heavy physical labor. A city is also "smooth" because it has a continuous flow and is always busy, and the business is never interrupted. So the sentence "smooth as a city" here is just used to compare the smoothness of the lady's hands with the smoothness of a city. However, this isn't a common expression to use.