It's because the search query is blocked. I think the more surprising thing is that it only effects the Image search results, and not the web search results.

It's because the search query is blocked. I think the more surprising thing is that it only effects the Image search results, and not the web search results. I checked the Video results, and Videos also appear blocked. It's possible that Image and Video search utilize the same word-filter list, and for some reason web-searches use a different list.