This is an optional visual branding area, and among the LibPress sites there are a few that have a header image (see Vanderhoof, Hazelton).
When designing a Header Image take note of the instructions:
Your theme works best with an image with a header size of 980 × 200 pixels — you’ll be able to crop your image once you upload it for a perfect fit.
Note: When implementing for the first time, you may need to contact us to help as the Logo might “disappear” (as in, its position would be behind the Header image).