So this has been really bugging me over the past few days (and forgive me if the answer is so simple). Let's say we're observing the Sombrero galaxy. It is about 29 million ly away and 50 thousand ly in diameter. So we should be observing the "front" of it at what it looked like 29 million years ago, and the "back" of it 29.05 million years ago. Why doesn't this extra distance change the galaxy's shape? If, for example, the galaxy was moving directly away from us in a straight line (not that it is), wouldn't the galaxy be compressed? Hope this makes sense.