It's All About Pattern Recognition

This photo was one of many returned on a routine Flickr Friday search for chess photos. They didn't look like chess pieces to me and the only reference to chess on the page was a white tag 'chess' while the other ~20 tags ('thanjavur', 'palace', 'tamil nadu', 'sculptures', etc.) were all colored gray.

Thanjavur Palace Museum and Art Gallery © Flickr user RealIndia.in under Creative Commons.

Flickr 'Help' explained,

Tags are keywords that make photos easier to find in Flickr search. The ones you add will show up in dark gray. Flickr’s friendly robots will try to help out by adding some for you; these will appear with just a gray outline.

An additional page explained,

Flickr’s image recognition uses pattern recognition to analyze the contents of images to determine the most appropriate tags to help you and others find your images using search. The process is fully automated, so no humans are ever involved in tagging your images. [...] Distinguish between tags you add and tags Flickr adds: Tags you add show up in dark gray.

Pattern recognition software thinks these are chess pieces? Can't argue with pattern recognition!