In the screen capture above from the charm school spisode of I Love Lucy we notice two small framed prints high up over the mantel. These automotive prints of early carriages are examples of framed prints that were sold in sets in the mid century era.  Examples of these are often seen on eBay.  Below is a closer look at the details as seen on the show.

The same two pictures along with a matching third print were also seen below the Maurice Utrillo picture on the back wall in other episodes.

Ref: http://www.ebay.com/itm/Set-of-3-Vtg-ANTIQUE-HORSE-CARRIAGES-Round-Wooden-Framed-Lithograph-Prints-Art-/232143635872