Yeah that's definitely a competitive school, but NSW seems extremely competitive. Even though its a public school, there are still a few students concerned about their academics. I guess in any selective school, the students know that 'dodgy behaviour' will not be tolerated so they aren't going to take the risk.
There's also the fact that there isn't this strict divide between selective or private or public. Like some public schools in Queensland really are terrible, but some are much better and almost to the standard of a private but they just don't have the name.