The Balcony Room (Das Balkonzimmer), Adolph Menzel
Link is to zoomable version on Google Art Project, downloadable file on Wikipedia, original is in the Staatliche Museum, Berlin.
In addition to Menzel’s wonderfully casual, painterly brushwork, this piece is noted for its interesting composition, in which a large portion of the image is “empty”.
To me, it’s a fascinating series of contrasts: the full and empty of the composition, as well as the dark-within-light values of of the chair in front of the open French door contrasted with the light-within-dark of the reflection in the mirror against the dark wall — repeated in the dark rug against the lighter areas of the floor, and the patches of bright sunlight against the darker area of the floor.
Even the two lamps aside the mirror are opposite value contrasts. Whether intentional or not, the two chairs facing opposite directions seem to reinforce the idea of opposition.