This thread is resolved. Here is a description of the problem and solution.
Problem: My WooCommerce products in main language shows the featured image on the listing products. Other languages don't show the future image.
Solution: In order to have the featured image and media files on the translation products, the Duplicate uploaded media from original and Duplicate featured image from original options (from the right sidebar when you edit a product) need to be checked.
This is the technical support forum for WPML - the multilingual WordPress plugin.