I often look words up quickly using Google Search. For example, I might search
define:belligerent to quickly get a definition, check my spelling, or find synonyms.
Today, for the first time, I noticed strange photos in the box with the definition. (See image below for reference.) The photos shown in the definition box do not seem to be Google Image Search results for the word being defined; if I do an image search for the same thing, the photos do not match. If not from Google Images, where do these images in the definition come from?
As a follow-up question: when was this feature added? I have never noticed it before, and use the definition feature of Google Search frequently.
Screenshot of what I am talking about (red box added for emphasis):