The headline is meant to be the space where the freelancer introduces what they do professionally. When clients are doing a freelancer search, they'll see it displayed just below the freelancer's name as a personal subtitle or tagline.

The simplest ways headline would be the name of the freelancer's work title, (“Ghostwriter” or “Accountant”). Users could also list their main freelancing skills, (“Photoshop | Adobe | FinalCut Pro”). Or, a freelancer could share a slogan that makes it clear what they do, (“Editing You Can Count On”)