There will be a few million years when residents of the two galaxies will have a very strange mismatch between what's happening locally and what happens everywhere else until they build something like the Hubble and look at a dark patch of the sky to see the billions of collisions happening in other galaxies too.
(He is suddenly struck by a vast system consisting of billions of stars, in a cataclysmic impact which completely obliterates him down to the last atom. Where the field once stood, there remains nothing but vast, endless nothingness, a reminder of the entropy which will one day consume all that has ever existed.)