Not seeing all comments, curious as to why

At this time this post supposedly has 13 comments but I only see six. I'm curious as to what's going on. Is it folks posting from instances that this instance is not federated to? Or is it because those users do not have English (or Undetermined) selected among the Settings > Languages options? Or is it a combo of both and/or some other stuff?

Are there any recommended user settings for engaging with this instance and are they posted anywhere?