When I recently did an image search, I was not surprised to see files from Wikimedia Commons pop up on top of the ca. 600k results, but noticed with pleasure that the first image originated from an Open Access source (PLoS Biology).
Interestingly, repeating the same search with “PLoS” as an additional parameter, another copy popped up, but the original was nowhere to be seen, and when I performed the search with the article’s DOI instead, there was only one result – the above-mentioned one on Commons, which is today’s Open Access File of the Day, as it highlights reuse from a different perspective.
I do not know why the original was invisible in this search. In general, my experience is that Open Access images do get listed in the search results but rarely prominently. Having an Open-Access image incorporated into a Wikipedia article may thus provide a considerable boost to the visibility and discoverability of the underlying research.