Blank image in Hueman theme

I’m setting up a new blog using the Hueman theme and can’t seem to find a way to place an image above the post. By default it’s putting a grey image placeholder (which shows the post title ‘Getting Started’ when I hover over it).

I’m sure it’s a *very* simple option but I’ve spent a couple of hours searching in the Dashboard as well as the Hueman Customize screens.

Any suggestions as to how to load this image (and/or remove the grey placeholder) is appreciate.

Thanks!

Ian

The page I need help with: [log in to see the link]