Whenever I see anything like that I always like to think that somewhere in the picture (obviously far too small to be seen) that there are stars with civilisation bearing planets orbiting them. Maybe ships moving between the planets and stars. Maybe they look at our galaxy and imagine the same thing. I'm sure in a universe so vast we cannot be the only intelligent species living in it.
I think nearly the exact same things; only I take it a step or two further, for both the worse and the better. I contemplate that the Earth-like planets and its homo sapien-like occupants (if they exist) could be in the infancy of their existence. What if they haven't even gotten to the fire and stone utensils yet? Imagine the amount of work this were the case. It is possible.
On the other hand, I postulate that it is the nth degree of an accumulation of what we've considered our best scientific fiction writings for the past three generations. There are no religions, no medical ailments, no war, everything is recyclable, so on.
Of course, like you said (and I've thought many times), there could be an exact match to the Earth/homo sapien correlation somewhere in existence.
Even further, where does existence end? Will we ever define this? I think of it in spherical realms coming in contact with one another at their cusps. I just don't know it all damn it! Or as a Christian would answer the questions...praise Jayzuz!