This episode seems out of place because it was originally supposed to air November 1, 1954, but was preempted. Although it's set in the New York apartment, it aired April 11, 1955, in the middle of the episodes set in Hollywood, California.
When Fred and Ethel sing the Phipps jingle the second time, William Frawley flubs the last line. Instead of singing, "First on your list of shopping tips," he sings, "First thing on your shopping tips."
When Lucy sings and dances to "Sweet Sue" in the kitchen, the table and chairs that are always part of the set are noticeably missing, likely to allow Lucille Ball enough space to dance.
From reversing and inverting the image, Lucy's burlap feed-sack dress reads "Sugar Sweet/DRIED CITRUS PULP/CONTAINING (illegible)/PASCO PACKING CO./DADE CITY, FLORIDA".