This is an image post. There’s isn’t really anthing special about it, other than selecting the “Image” post format. We’ve still just applied a featured image and set it to link to its enlarged version in a lightbox.
A post with a banner
With every page and post of your site, you’ll find a “Banner” meta box. With this, you can apply a banner to to top of the page. This is separate from adding a featured image.