When I made the Mori and Juniper coffee pic a couple people on Instagram asked to see a comparison between their dynamic in Dorm Days (they're 18/19 years old) and current day around the time Starbound comes around (when they're around 23/24 years old). They're two people that go through a lot together and a big part of their story is them trying to get past their own hang-ups (Juniper being closed off and making assumptions and Mori being naïve and navigating her people-pleasing tendencies), especially in the beginning when they're really sensitive around others. So when they do get through their issues, they're much more open to becoming friends.
And it's not a quick progress; it takes years to forge the friendship they have in the second pic. Don't get me wrong, I love stories that have the two main characters hit it off immediately and they just have a few speedbumps along the way. But I think the interesting part of a story like this, where neither is exactly open at first, is that they both grow and learn despite being thrown together unexpedtedly.