Every time Alex makes his special lasagna he mentions that he didn’t have real cheese. This is a subtle nod that cows are selfish jerks. They flat out refuse to acclimate to the vacuum of space. This is why Garfield won’t leave Earth, sasa ke.
The Belters, people born and raised in the asteroid belt, speak a creole language. Even with the subtitles on, I cannot understand what they’re saying. This is a subtle nod that not only am I an Earther, but so is the subtitle provider. And Google translate.