When the citizens are leaving the cells, Andy speaks to one woman and says "Hey Nellie, it's a nice dress". This would be the initial appearance of the extra that came to be known as Nice Dress Nellie. She would appear in scores of shows over the next 7 years, but would never again be named or credited. Despite the scores of appearances, she would never utter a line.
(Barney is reading Aunt Bee's charges as Andy is trying all of the arrest cases)
Aunt Bee: You say one more word, Barney Fife, and you'll regret it!
Barney: It's like they say, 'Once burnt, lesson learnt... one mistake, better cake... once bit, best forgit.'