There are a number of parts to that question.
There are different standards between the two clauses. I addressed the reporting standard in the question from Mr. Lee, but the notification standard applies when a service provider discovers it on their own system or it's brought to their attention by one of their subscribers; when they investigate, it's apparent to them that whatever is there is child pornography. If it's not apparent to them, like the baby in the bathwater, or a piece of art, then they haven't met that standard of belief that there's child pornography.
In many ways, it works. If you're prosecuting this case, there are a number of different hoops the crown would have to jump through in terms of proving that someone had reasonable belief, but the defence is always subjective too.
The baby in the bathwater or the art piece are areas where someone would say they didn't have belief that it was child pornography. The way it was crafted is more along the line that you know it when you see it. So if there's--