Kimsooja (b. Taegu, Korea, 1957, South Korean) - A Reflective Palace Of Rainbows, 2006 The Palacio de Cristal was originally built in the late 1880s in Madrid, Spain. In 2006 artist Kimsooja transformed it into this rainbow reflecting palace. Installations
The invisible people, according to Jin Young Yu, are the people of have decided to stay away from others, instead of trying to fit in, they have climbed into their own space and denied any kind of interference.
Her website is all in Korean, so I have no idea what it saids, but I found this really good interview at arrested motion. It’s definitely worth reading