I read it as a form of energy generally thought to roam free can’t move in space/exchange its energy until a spot somewhere else has already received it. The delay should be measurable by the speed of light for the transmission of the energy wave/particle, but the final effect (heat transfer) occurs instantaneously—even if totally across the universe.
It has a parallel with entanglement.
Thank you. So the “next step” for me seems to be what we are witness to in what we refer to as “reality” is not so much “Plato’s Cave” or even Kesey’s “Movie Theatre” but something infinitely more complicated. Mass and distance are almost illusions connected by light. Something very strange is going on here. And think about the constraint you mention in regard to “it seems the photon can’t move until it has a place to land”. So photons that left stars in galaxies billions of light years away left that star before our planet, much less my retina, were even created? Sort of smashes our concept of time.