By default, WooCommerce will only show star ratings for products with ratings greater than zero. That means star ratings are not displayed until a product has at least one review. If you’d rather always have them displayed, use the code in this post.
The developers of the JetPack WordPress plugin decided to put a layer above the featured image thumbnails of “related posts”. This gives the images a faded look which you may not like. The CSS snippet shared here will help you disable this feature.