If added to the Footer menu, social links are automatically detected and converted to SVG icons for the supported social media.

Twenty Twenty-One supports nine post formats: link, aside, gallery, image, quote, status, video, audio, chat. You can pick your post format in the Status & Visibility panel of the editor’s settings.

To have a look at how the Twenty Twenty-One theme handles post formats, navigate to the template-parts/excerpt folder and pick template. For example, open the excerpt-image.php file in your favorite code editor. In that file you’ll see the following code:

* Show the appropriate content for the Image post format.