Oh, as a matter of interest, the five small spheres are a light meter. The white highlight on the larger central sphere indicates that there is too much light in the scene at that point. That's because the middle sphere is positioned just underneath the point light.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)