The project image can be displayed on top of your project page, just inside the project description. This image is also the image that will feed through to your Whitehaven landing page, if that is the template you have selected for your EngagementHQ.
In order to include an image into your description, navigate into your project and click on 'Manage Project Image'.
As you can see above, you will have a couple of different options. You can opt in to use a 'Caption' and a 'Description', which you should do for SEO purposes and, finally, you can select the type of layout. This will determine how the text wraps around your image. You can even choose to NOT display the image. This might come in handy if you want to include an image for your home page, but not have it show on the project page.
Click 'Update' when you are ready to have your changes go live.