Sentence:  And Dwayne again carried on a wry talk with the Creator of the Universe, using a robot as an unfeeling <WSD>conversation piece</WSD>. A lot of people in Midland City put useless objects from Hawaii or Mexico or someplace like that on their coffee tables or their livingroom end tables or on what-not shelves—and such an object was called a <WSD>conversation piece</WSD>. 
Meaning of the word marked with <WSD> tags:  An unusual item, such as a painting, or a tabletop knick-knack which encourages comment from visitors, and so helps to break the ice.