When customers come to your store from search engines, they need a confirmation that their choice was right, so they look for common words at the address bar and if don't find any, they close the page, which isn't the best result of their visit for you. Now you can have nice-looking and search engine optimized urls for category pages sorted by any product attributes. For example:
Along with icons for layered navigation, you will also have an option to upload an attribute icon for product pages. The icons will link to the list of all products sharing this attribute option (e.g. some product quality, let’s say brand or color), this will create additional cross links, which will make it easier for customers to find similar or matching products and improve your site SEO. Moreover, easy to comprehend icons on product pages will help the customers to make a choice faster and better. See the example here.