I assume they will publish a journal article with details like diagrams eventually. This 2022 journal article by the same researchers has a bunch of details and photos of the natural palm cockatoo hollows they were trying to emulate: http://dx.doi.org/10.20938/afo39113124

This ABC article from last year about the project contains some more photos of the artificial hollows and also details of a long-running artificial hollow project for Carnaby’s cockatoos in WA: https://www.abc.net.au/news/2025-10-23/artificial-nest-trial-for-cape-york-palm-cockatoo/105925758