Clicking on Fetch & Render button after adding your website link will give webmasters the option to specify how Google should fetch it, desktop, smartphone or featured phones. Then it will show you a visual representation of what Google renders and more importantly, at it will show you which resources you are blocking GoogleBot from crawling.
Notice what is blocked, all Google resources. :)
We recommend making sure Googlebot can access any embedded resource that meaningfully contributes to your site's visible content, or to its layout. That will make Fetch as Google easier for you to use, and will make it possible for Googlebot to find and index that content as well. Enjoy ! :)