This is a "signoff" box. You can create as many signoffs as you want in the theme options and then insert them into posts via the shortcode builder. Or you can insert a one-off signoff on an individual post basis. The possibilities are endless.
What is a "signoff"? Think of it as a way of telling your readers something before they go, maybe something that you always want to remind them of when they're done reading articles on your site. Maybe a reminder to check out your social profiles, signup for your newsletter, or contact the editor to offer feedback or report an issue. They are very versatile and can be used for whatever you need.