The reflections that occur in the listening environment can't distinguish between the recorded direct sounds and the recorded reverberation tails, it "makes a soup" of everything and treats it all as one single continuously changing sound, but as long as the early reflections are kept under control, the diffuse field of sound the late reflections adds to the equation can add a sensation of envelopment (even if this soup of diffused sound contains a mess of every single sound in the recording, no matter if it happens to be recorded direct sounds or recorded reverberation tails).