This certificate is not required to photograph children. It is used to demonstate to clients who seek to pay you to work with children that you are not banned by law from working with children. That is very clear in the linked information.
Looking through the content on the site, on the Facts Sheet page it says...
If you meet those requirements or needing to have a certificate and you don't have one you fined $2,200 (not $22,000).Who needs a Certificate
You will need to get a certificate if:
•you are self employed
•and you work in one of the settings defined in the Commission for Children and Young People Act 1998 as child-related work settings
•and your work requires that you have direct unsupervised contact with children (under 18)
•and you are over 18 yourself.
It also goes on to say...
If you are not receiving payment or do not intend to sell your photos, you are not self empolyed.From 1 May 2010 self employed people who work with children, such as music and dance tutors, sports coaches and nannies, will need a certificate that says they are not banned from working with children in NSW.