"when Bob receives Alice’s bits, he uses that information to apply one of four transformations to his photon. It is Bob’s action that changes his photon’s state

"when Bob receives Alice’s bits, he uses that information to apply one of four transformations to his photon. It is Bob’s action that changes his photon’s state into the state of Alice’s original photon. And that is the only time that Bob’s photon changes state." I disagree with this particular bit. The state of Bob's photon changes exactly when Alice does her measurement [1]. Why? The state of a photon is given by 2 real numbers (infinite bits). Bob receives 2 bits of information from Alice so his 1/4 operation can't change the state of the photon to an arbitrary state. The 'magic' does happen when Alice measures her state. After her measurement Bob's photon is in one of four possible states, which are the same up to 2 swaps. The 2 bits of information are needed to find out which swaps to perform. This swapping step nicely prevents faster-than-light travel. [1] Caveat. In a relativistic universe, ordering of events depends on the frame of reference. All arguments carry through when this is taken into account. Edit: I should explain how this saves relativity. No measurement (weak or strong) can distinguish which pre-swap-state Bob has. You can try to be clever and ask Alice to teleport millions of photon states to Bob. But that doesn't help either because each of the four states are equally likely in the whole ensemble. So you need 2 bits of information per teleported photon state to get the correct final state each time.