I don't understand what you think is shown "through" the roof of the clubhouse (or cars, for that matter). That's just the roof:
https://i.imgur.com/cDF8Fsr.jpg
Now take a look at this map image, and go back and forth to see if you feel that the X i marked is a reasonable approximation of the photographer's location
https://i.imgur.com/fvj0ZPj.jpg
Now take a look again at the SAR image and tell me if you can see any artifacts from the front of the building through the roof (hint, zoom in and look for the curved line of bright dots :) )
https://www.sandia.gov/radar/_assets/images/gallery/ka-band-...
The brick wall at the front, though, has the exact same curvature as the dots, dead-on.
But now that I have a better understanding of the layover effect I think it might just be that the satellite is looking from where it looks like the sun is shining, and it's directly imaging that front window frame and brick wall. Need our SAR pro to comment :)
There appears to be a couple tables that are hiden from Google's satellite view but clearly visible to the bottom right of the building in the ka band SAR image.
While I can't find the image online earlier than 2010, there's an ieee research paper titled TanDEM-X for High-Resolution SAR Interferometry from 2007, so it certainly could predate the awning.