There is one spot for a painting in the room.
Additionally, there is a water fountain for use with Realistic Needs and Diseases.
After buying the upgrade for the backroom, a set of crates will appear that will allow you to set up and switch between a Follower's Room and a Children's Bedroom. This is also where you can set up the Patio area. Once the upgrade is bought from Bits and Pieces in Solitude, switching between the two can be done as often as you like and takes about two in-game hours.