Oh, hey, you gave me an idea (Destiny)

by ZackDark , Not behind you. NO! Don't look., Tuesday, November 21, 2017, 05:04 (2361 days ago) @ Kahzgul

Now, if the expansion took place on a plane (we know this one doesn't, but hey - it's kind of represented that way so I'll go with it), you *could* see the light as expanding if your viewpoint was perpendicular to the plane of expansion. BUT in order to see a galaxy-size pulse from far enough away that you could see the entire milky way in your field of view, you're talking hundreds of thousands, if not millions of light years, which means it would take an equal amount of time for the light to reach you.

The camera is perpendicular to the bubble in the 4th dimension, so you see it expanding AND the viewpoints where you can see the system and galaxy are irrelevant to the time the ships receive the pulse.