During the first two scenes that show the exterior of the dress shop, when Lucy and Ethel return their dresses and when Ricky and Fred pass by, a mailbox is stationed in front of the neighboring Morris Hull Book Shop. In a later scene, when Lucy appears disguised as an older woman in a wheelchair, the mailbox is missing.
The sidewalk and the floor of the dress shop are the same surface.
The building and storefronts across the street from the dress shop is obviously a cloth backdrop; complete with wrinkles.
After Lucy rushes home to intercept Mrs Hansen's phone call, she answers the phone posing as the maid. The only conversation is Mrs Hansen asking for Ricky, Lucy telling her he only speaks Spanish, and Lucy asking if she speaks Spanish. At no point does anyone mention anything about a check. Yet Lucy tells Ricky a friend wants to know how to say "the check is good" in Spanish. If she was really the maid, as Mrs Hansen believed, she wouldn't know about the check.