Google announced yesterday they have added captions to the image search results in Google Image search. They get the captions by using the title attribute from the web page the image is on.
Here is a screen shot of it in action:
Here is a before and after:
Danny Sullivan of Google said on Twitter that this comes from the "HTML title tag" and it is "not used in any special way for ranking the image." He also recommended that he "would suggest people keep captioning images exactly as they've always been advised to."
Here are those tweets:
The caption comes from the HTML title tag and is not used in any special way for ranking the image, to my understanding.
— Danny Sullivan (@dannysullivan) March 13, 2018
I would suggest people keep captioning images exactly as they've always been advised to. What is the image about?
— Danny Sullivan (@dannysullivan) March 13, 2018
This is rolling out now globally on the Google app (Android and iOS) and on mobile browsers.
Forum discussion at Twitter.