The careful attention to detail shown for the store's various and sundry departments and merchandise is typical of cartoons from this era.
Stacy's department store is a play on Macy's flagship NYC store. At the time of this short, major department stores carried a multitude of items, including pets.
Tweety makes an escape using an old fashioned pneumatic tube system, which was used to deliver paperwork to various departments in a business.
Although the audience never sees the French bathing suits Sylvester is so appreciative of, it's likely they were fashionably scandalous for the era. The famous bikini swimsuit was invented in 1946, six years prior to this short, by French designer Louis Réard.
One of the few times Tweety is actually shown flying, if only for a brief moment.