the sky in the tops of the windows was perfectly blue , vibrantly blue , and the sunlight was pouring in on the polished floor , and all the world appeared glorious in the brightness- the bare tree branches with their white trimming of snow , and the snow-covered roof opposite , and the room itself , full of whiteness and lustrous color , light glancing off the mirror , and the crystal glass on the dresser , off the brass knob of the bathroom door .