Originally thought this was a Garrha spp. due to the banded.spotted antenna but couldn't find a match. Now think its probably S. mimica in part because its more elongate, although that species is very variable. But see Ian McMillan's photo on the ALA which is a good match: https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:639a959b-3fd9-41bf-aeab-39e17fc9250a#gallery
If you say so, but it does not resemble any of the 137 Garrha species illustrations on BOLD at http://v4.boldsystems.org/index.php/TaxBrowser_Taxonpage?taxid=77403 I think the pattern on the antennae may be a lighting artefact.
See also very similar moth at 'Gippsland Lakes Lepidoptera' (Ento, Soc. of Victoria), p. 25 and at page 30 'Morewell National Park Lepidoptera and Neuroptera' (Harris and Marrriott 2018) which identifies the moth as 'Garrha MNP sp.(4)'. Also Jack Crosbie on ALA: https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:49972bf5-acbe-4389-9c2c-58205d8028bb#gallery ; and iNaturalist: https://www.inaturalist.org/observations/37447124 . Also sightings 435788 and 22629.
Very good. Thanks. I agree. Given their variability, I think this could also be G. limbata or G. sincerella. I see that G. limbata is not illustrated on the BOLD website, so that website has not as complete a coverage as I hoped. I think previous relevant sightings are 4357880, 4357213, and 4357880. I could not find 22629.