That's a maintenance notice, like "this page needs cleanup" or "this page needs sources". You can copy the templates they have, or grab one from the Templates wiki.
I was told that thoughts behind the big ones, with a quote and an image, are outdated, though. Going to a site like Wookieepedia and seeing 3-5 notices about what the page doesn't have at the top of a big page can weird out casual readers. Best practice would be 1) make them minimal 2) make them uniform in design and 3) put reader-oriented templates at the top, editor oriented templates at the bottom of the page.