For the record it appears the law in Australia relating photographing paintings and murals is very different to the law relating to photographing sculptures in a public place.
https://www.artslaw.com.au/art-law/e...ic-sculptures/
""The exception to copyright infringement under Section 65 of the Copyright Act allows anyone to make drawings, take photographs or film a sculpture that is on permanent public display, without infringing copyright in the sculpture. A work is on permanent public display where it is in premises open to the public or permanently in a public place. Permitted reproductions extend to the adaptation of the work into digital form for both commercial and non-commercial reproductions. However the exception does not extend to other artistic works, such as paintings, murals or mosaics that may be permanently on public display. In these circumstances, permission of the copyright owner is required to avoid infringement.
As a consequence, where sculptures are on permanent public display in Australia, commercial uses are allowed without the permission or remuneration of the sculptor. That is, a sculptor has no legal grounds to demand payment for any visual reproduction of the sculpture as his or her copyright does not extend to the general control of reproduction rights if the sculpture is publicly situated. ""
In addition , all sculptors with work in the exhibition had given permission for photographs. There was one work you could not photograph , but I think that was more due to it's sexual explicitness , rather than any copyright issue.