DO WE NOT JUST LIKE NICELY PAINTED BARE WALLS ?
Do we always like to be reminded of moments ?
Do we always want to stay in touch with reality in any subtle way possible ?
I would say more because of the latter than former. Every wall art, whether it's of cities, landscapes, animals, etc keeps us in a constant touch with the reality and tangible elements of the world.
One example would be the one shown above. You can be in any part of the world and yet can refresh your memories if you had ever visited the place or simply can just be reminded of it's physical existence.