This is the first appearance of Mary Jane Croft on a Lucille Ball sitcom. Croft would later go on to play Evelyn Bigsby in Return Home From Europe and Betty Ramsey during I Love Lucy's sixth and final season. Croft will later go on to have more significant roles on Balls's two other series The Lucy Show and Here's Lucy.
In the final scene when Lucy & Ethel realize they've been had, they jump up to hit their husbands with the linen napkins. Lucy's napkin flies out of her hand behind her. She grabs it and starts hitting Ricky without skipping a beat.
The $500 paid to Lucy and Ethel for their "Martian women" stunt is shown onscreen in Mexican revolutionary (Bank of Sonora) currency. The notes appear to be the 1915-issue 5 peso denomination (given the shapes of the engraving seen on the ends as Lucy and Ethel fan them out in the final scene), with white zeros painted after the large "5"s on the reverse to make them look like "50"s. (The zeros are off-center on close examination.) It was the practice (and likely the law) in the 1950s not to show real U.S. currency onscreen. Other shows of the period also used Bank of Sonora currency, such as The Perfume Salesmen (1957).)
In a scene set at the top of the Empire State Building, it is said to be the tallest building in the world. This was true until the completion of the North tower of the World Trade Center in 1970.
When Lucy gets home from the Empire State building she doesn't notice Mrs. Trumball is missing.