One of the reasons it is believed to have been used as a dining room is the crystal chandelier (seen from the dining room picture post linked above and also in the top picture of this post). Like I mentioned in the dining room, all other rooms in the PT have neoclassically appropriate lanterns. The room also features beautiful gilded bronze sconces which have been electrified and add soft lighting.
The room features a beautifully colorful mantelpiece of red Italian Griotte marble with a matching hearth which is featured elsewhere in the room (in the floor at the window surrounds). The red curtains play up the use of this red stone. The elevation below shows the wall as it is featured in the Boston Architectural Club Yearbook from 1913.