After some testing, Google yesterday officially rolled out the new design for the image search results on desktop. The new design adds titles/captions and the URL to the image thumbnails, adds images to the top filter options and more. As I covered at Search Engine Land - the new desktop design brings it more inline with the mobile version of the image search results.
Andy B. from Google shared the news in the Google Web Search Help forums saying:
Since the original posts on this thread were about temporary experiments running for Google Images, want to clarify that most users should now be seeing the newly announced and launched Google Images UI (official blogpost with more info).We appreciate your continued feedback though! We'll keep monitoring this thread and other feedback sources to shape and improve future iterations of Google Images.
With this, as we covered earlier in the week, are new ranking algorithms for image search.
Forum discussion at Google Web Search Help.