We found ourselves in a thick white metal cage that opened into the Medical Records room—an empty, warehouse-sized room with no staff, no patients, no chairs, no visitors, and no medical records. Its windows were bolted shut and covered with wire and dirt, its gray carpet bunched in ripples from decades of foot traffic. A waist-high cinder-block wall ran the length of the room, separating the waiting area from the area marked AUTHORIZED PERSONNEL ONLY, where several rows of tall metal shelves stood empty.
— The Immortal Life of Henrietta Lacks by Rebecca Skloot
Does this mean the carpet is folded in a wavy shape? I can't visualize it.