EDIT: I've come to realize the problem I'm facing is a misunderstanding of how Modular Pages work in Grav. It would seem Quark only displays hero images with a Modular page (please, correct me if I'm wrong about this). However, I'm struggling to find good documentation on how to set up a Modular Page using the Admin Panel and with this being my first attempt at using Grav I'm struggling to get up and running.
I know I'm missing something very, very simple but I cannot seem to figure this one out!
All I want to do is display a header/hero image using the default Quark theme. On their Github page you can see a header/hero image demonstrated (e.g. the picture of Einstein): https://github.com/getgrav/grav-theme-quark/blob/master/assets/quark-screenshots.jpg
How do I get a page to look like that? I've tried adding photos to the page (and not referencing them in the page), and I've fiddled with the Headmatter but to no avail.
I can get a header/hero to show in other themes (e.g. Aerial - accomplished by uploading the image to a page but not referencing within the page), but for the life of me I cannot get one to show up on Quark.