I tried this on a local site and noticed that when translating a product category, the thumbnail image is not copied over. I tried this with WPML Media installed and still did not work.
I will check if this is intentional or if there is another way to make the image copy over when translating.
As a workaround for now, you can add the images again to the Hebrew product categories. Go to Products -> Categories and switch to Hebrew using the admin language switcher (/wp-admin/edit-tags.php?taxonomy=product_cat&lang=he&post_type=product). Then you can edit the categories, adding the thumbnail to each.
I will update you when I have more information about this, please update me on if you manage to solve your issue in this way.
