That topic is actually for adding the a Category image to the hero section of a Post Category archive. It won’t add any images beside the Woocommerce Category Widget.
The only thing i could find is this Woo doc:
https://docs.woocommerce.com/document/woocommerce-product-search/widgets/product-filter-categories/
But it requires the Woocommerce Product Search Extension ( paid )
Alternatively this would require custom development.