After a worldwide roll out of Google Suggest for web search; Google now showing up search suggestions in Image Search. The suggestions from Google Image Search include many specific words like "paintings", "pictures", "wallpaper", "cartoon", "photos", "landscape", "logo". Google Suggest is now enabled by default in 3 Google search engines: web search, image search, Google Video and it can be disabled from the preferences page or by appending &complete=0 to the URL.

Source:→ Google OS