Haven't read this story before, but the final sentence is probably just a way of saying it was cold and barren both outside and inside. When something is described as wintry, it usually means cold and barren. It says that the "harsh thin light" is seeking something through the windows, but only finds a cold and empty laboratory. So, the wintry outdoors is matched by the cold, unoccupied room inside.

It's a complex passage, difficult to parse. It poetically contrasts hot and cold to create a striking image. I would add a little to the previous comments. The first word, "cold", is actually describing the "harsh thin light". This contrasts strongly with the fact that it is summer outside the room, and the temperature in the room is actually hot. Yet the furniture of the room is emotionally and visually cold and sterile - a laboratory. Cold, barren light "sought" something, and only the cold, barren furniture responded (by being coldly illuminated). Wintriness responded to wintriness. Very poetic.

It's poetic and evocative language. I'm not entirely sure what is "responding" to what. The reflection of light on shiny things can be cheerful, but not here. The porcelain is "bleakly" shining in the "harsh thin" light. Possibly the wintry porcelain is "responding" to the wintry light by shining "bleakly." He's certainly trying to make the laboratory sound emotionally cold. There are no humans there, but even if there had been, they would have only been "pallid shapes of academic gooseflesh." Gooseflesh is the way skin becomes bumpy and the hair stand up when you are cold... or frightened. So he's saying that even the human beings are not really human, they are just "academic gooseflesh" and that they, too, are cold. He's piling image upon image, every one of them suggesting emotional coldness.