The framed print is of a Grandma Moses original painting entitled “So Long”. It is on of two prints seen near the entrance door of the Ricardo’s living room set.

Thanks to the generous commenter below we have an ID for the second  Grandma Moses print which  appears to be “The Old Snow Roller” 1948

Anna Mary Robertson Moses (September 7, 1860 – December 13, 1961), better known by her nickname of “Grandma Moses,” was a renowned American folk artist who only began painting earnestly at the age of 78. Grandma Moses was a celebrity at the height of her popularity when the I Love Lucy show began in October 15, 1951 so this print would likely have been recognized by many of the I Love Lucy viewers.

To give you an idea how famous she was at the time:

• In 1949 President Harry S. Truman presented her with the Women’s National Press Club trophy Award for outstanding accomplishment in art.
• In 1950 a documentary of her life, directed by Jerome Hill  was nominated for an Academy Award.
• In 1950, the National Press Club cited her as one of the five most newsworthy women .
• In 1951 the National Association of House Dress Manufacturers honored her as their  Woman of the Year.
• In 1948 at age 88, Mademoiselle magazine named Grandma Moses “Young Woman of the Year”.
• She was awarded two honorary doctoral degrees. The first in 1949 from Russell Sage College and the second two years later in 1951 from the Moore College of Art and Design.

Find Grandma Moses prints on eBay

Grandma Moses from Jerome Foundation on Vimeo.

Ref:
http://en.wikipedia.org/wiki/Grandma_Moses