How do I change the image description?
To change an image description, you must change the text next to the image and the image
title attribute values. Then you'll have to wait a bit for the robot to notice the changes and re-index them. After it's re-indexed, the image will display in response to different queries.
Note. Yandex returns images that match the user's query best. But image description isn't the only ranking factor. This means that there might not be any query words on the pages where the images are found.