Design change of blog index using Liquid template language, HTML, CSS

I need a design change done on the blog index of a [login to view URL] site (formerly Fedora). They use the same Liquid templating engine from Shopify. The current blog index shows a preview of each post (but only text). What I want is that the blog index previews text + the first image of the blog post as well. If the first image in the blog post is full width, the blog index preview will simply show the image full width and the text preview below. if the first image in the blog post is only half width or less, then the blog index should preview the image next to the text. I need to be able to see the changes that have been made in the blog index file.