One remaining question I had after watching Grant's video was that, although the collective behavior of a bunch of light waves made sense via interference, how

One remaining question I had after watching Grant's video was that, although the collective behavior of a bunch of light waves made sense via interference, how would a single photon's direction would change upon entering the medium? The best answer I could find on physics stack exchange was that the single photon's wavefunction is delocalized, so that the photon's wavefunction, in fact, interacts with the entire medium, instead of at a single point. Is this the correct way to state this phenomenon or is there a better understanding of how the light emitted from a single photon interacting with a medium would bend?