If you were outside our galaxy and halfway to the Andromeda galaxy, your destination would appear redder than it does from Earth because we observe the universe from deep inside a galactic gravity well that accelerates all photons which travels down the gravity well into the Milky Way and are lucky enough to bounce off a telescope mirror and be observed.
What are some other effects on observations of the universe outside our galaxy created by our unique rest frame? How would different would the universe look from outside of our deep galactic gravity well?