However it is just a single image of a board, and there are no active symbols on the board drawing to anchor routes to.
Am I supposed to just drop a connector and my components to visually align with this image, then remove the template image? Or do I some how connect routes to the connector images on the template?
I’m able to close out the answer to my own question. I had mistakenly added the component (from the library) directly to my board layout, instead of my schematic. As such, it only existed there as an image, instead of an electrical component.
Adding it instead to the schematic, gave me an electrical component I could interconnect my other components to as usual, for a complete Hat.
Moving then to the board layout, everything appeared in the proper layer as expected, including: Vias, Holes, Pads, Dimensions, etc.