From the point of view of the observer, any starlight beyond and behind the galaxy being observed, would be push away curving around that galaxy and can sometimes have a mirror image on both sides of that galaxy.
I thought, if Gravitational Lensing is causing such a huge optical effect on...
I too have wondered about the theories and conclusions derived from "only" the Red Shift observation. What lead me to even ponder this was that they say, the further away a galaxy is, the faster it appeared to be moving away. I was bothered by how the Universe could be expanding away from us...