You can add the category image and description by adding the following to the archive-product.php
file after <?php if ( apply_filters( 'woocommerce_show_page_title', true ) ) : ?>
that if statement:
if (is_product_category())
{
global $wp_query;
$cat = $wp_query->get_queried_object();
$thumbnail_id = get_woocommerce_term_meta( $cat->term_id, 'thumbnail_id', true );
// get the image URL
$image = wp_get_attachment_url( $thumbnail_id );
//if you only want the image, uncomment the two lines below
//list($width, $height) = getimagesize($image);
//echo '<img src="'.$image.'" alt="" width="'.$width.'" height="'.$height.'"/>';
$cat_id=$cat->term_id;
$prod_term=get_term($cat_id,'product_cat');
$description=$prod_term->description;
echo '<div class="category-description" style="background-image:url('.$image.');">'.$description.'</div>';
}