Train tracks run through a living room. A couple of people sit on a sofa and sofa chair while ignoring the tracks.
Train tracks do not run through living rooms.
Why is there a train track running through the living room?
Something's different... is that a new lamp?
scene: a living room description: Train tracks run through a living room. A couple of people sit on a sofa and sofa chair while ignoring the tracks. uncanny: Train tracks do not run through living rooms. entities: Track_(rail_transport), Meeting. caption: Something's different... is that a new lamp?
People often make small design changes to rooms, and it's usual for guests to notice that something has changed (but perhaps be unable to specifically identify the changed component). The person notices that something is different about the room (obviously: the train tracks are the unusual piece), but fails to identify it, instead pointing towards something more benign.