Put the meaning into your own words.

A bright plastic chair looked incongruous in the solemn antique room.

For an exhibition about everyday writing, Selim assembled an eclectic collection of notebooks, shopping lists, postcards, and handwritten signs. He did not want a homogeneous display in which every object looked as though it came from the same desk. One polished metal trophy, however, seemed incongruous beside the paper objects because its connection to writing was unexplained.