What are you in the mood for, and does it match the wall?
Does it realty matter?
Yes and no.
Art can help set the mood, it can save you from a bad day if you let it.
Pick one that you love, art that speaks the same language as you.
Love the art and placing it where it work for you and is in harmony with its environment. That is You + The wall + The couch.
Remember; Art lover you can always paint the wall and get a new couch to match your art.