You can attach files to a post, as many as you want and images too. Just click on the pictures/attachment icons on the right of a post and start uploading your files. This content has some example attachments below and pictures on the right. By default pictures are always arranged on the right of a content onless it's not a partial content in which case the first picture will be shown on the left and when post selected all of the will be shown on the right just like here, but you can move them to any place from CSS.