Problem:
Translate image information (caption, alt text, description) into a second language. Solution:
There are two ways to add the image information to the translation image:
1. Go to WPML > Settings > Media Translation section > Enable option "Translate media library texts with posts". Then you can translate the image info when translating the post.
2. Activating the plugin WPML Media Translation > Go to WPML > Media Translation > Edit each translation image and translate the image info manually on your site. Relevant Documentation: https://wpml.org/documentation/getting-started-guide/media-translation/#id5
