Or is this a variant of the "counterintuitive" long shadows of mountains at sunrise/sunset? e.g. https://www.fox13seattle.com/weather/skies-erupt-in-color-du... shadow from underneath the cloud layer.
I'm sure I've seen a picture of the long downwards shadow of a mountain on a desert or plain taken from the top with the sun behind the photographer, but the search seems to be sufficiently AI poisoned now :(