Google's John Mueller said recently on Twitter that when it comes to images, images being unique does not mean the image is higher quality. John said "IMO with images in particular, uniqueness isn't equivalent to higher quality."
So having a unique image that you took yourself, doesn't necessarily make the page that image is on rank any higher in Google Search nor does it necessarily help the image rank higher in image search for specific queries. Although it might, if it becomes a super popular image?
John Mueller said previous that it is worthwhile to have unique images on pages but he did add it doesn't help you rank directly with web search, but overall, it is still good to have. John also said that having duplicative images, like stock photography doesn't hurt your rankings.
Of course, if you want your dedicated and loyal readers to be engaged - sometimes having unique and interesting images does help entertain your readers. But no, that is not a ranking factor.
Here are those tweets:
Would you consider an image unique if it's resized? rotated? changed to a different viewpoint or angle? IMO with images in particular, uniqueness isn't equivalent to higher quality.
— 🧀 John 🧀 (@JohnMu) August 18, 2021
Forum discussion at Twitter.