By default, WooCommerce displays a neutral and uninteresting category image placeholder in those cases where a category has no explicitly set thumbnail. This plugin simply replaces the placeholder image with a product image from that category.
User can choose whether to use a random product or the latest product from that category.
Feature requests welcome, please post in the support forum.
There is no complicated setup, simply install the plugin and configure WooCommerce to display categories. Any categories containing products but without a category thumbnail will now display a product image.
To switch between random and latest product display, see the settings page under WooCommerce > Settings > Auto Category Thumbnails.
More options coming soon.