There are multiple page headers available in this theme, you can also add your own.
Choose a default image for your entire site, randomize them on each page, or choose a different header image on each page of your website.
Examples below:
To change the overall website header go to Appearance > Header in the WordPress admin area.
To change the header image on a per-page basis please make sure the “WP Display Header” plugin is installed, then you can pick an image per page like so: