WPML Media Translation allows to choose images and other media for translated content. You will be able to provide replacement images for content in different languages and translate the meta texts of those images. You should use WPML Media Translation when you are using WPML Translation Management and you need to show different images for translated content.
To understand when you need the Media Translation plugin, first see how you would translate images without it. WPML core plugin allows you to manually translate the images and media in your content. In this case, you translate them just as any other part of your pages.
You would use the WordPress editor to edit translations. There, you can upload different images for different translations.
However, when you use WPML’s Translation Management, you don’t edit each translation in the WordPress editor. You edit translations in a dedicated editor for translation (inside WPML or by a translation service). In that case, you need a separate tool to provide translation for images. This is WPML Media Translation.
Some of your content may include images containing text (i.e., screenshots of user interface items) that must be presented in different languages.