Huh that's a cool observation. I think there might be more ambiguity there though. For example, I could (and in my case would probably) also interpret the secon

Huh that's a cool observation. I think there might be more ambiguity there though. For example, I could (and in my case would probably) also interpret the second response as not being "friendly" exactly but as defensive and irritated. Only someone who is worried about being regarded as inferior or believes that you're acting superior would make that kind of overly demonstrative response. A peer would probably just echo your tone and just say "Ok". Not saying you should psychoanalyze too much or that your interpretation is wrong but be on the lookout (especially via written communication) for when kindness isn't actually kindness, but deference or defensiveness.