The underside image clearly also shows the male antennae with the long pectinations. However what concerns me is that this moth shows quite a straight black line in the hindwing, whereas all images of D. exsuperata I've compared it with elsewhere on both the ALA and the Moths of Victoria CD show D. exsuperata has a distinctly curved, not straight black line in the upper view of the hindwing. A key provided on the Moths Victoria CD comparing three Ectropis spp. ie. E. excursaria, E. bispinaria and E. calida would suggest this specimen would quite closely fit E. calida (i.e. it has a male antennae with long pectinations and a relatively straight black hindwing line). For comparison there is one image of E. calida on the ALA, see http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:2f23f390-a830-46ce-bbf9-37aa37d0a6f1#gallery
I reiterate I doubt this speciment is D. exsuperata because of the straight hindwing line whereas in the D. exsuperata examples I see online the main hindwing line is strongly curved. The antennae is pectinate (can be seen better under magnification) consistent with a male Ecropis sp. but the pectinations vary in length: shorter at the base, longer at mid-length and shorter at towards the tip (i.e more lke P. cognata, but not aspronounced). These pectinations are quite unlike the short even-lengthed pectinations shown for E. excursaria and E. bispinaria on MoV (see the Part 7 supporting PDF file). As mentioned above, there is a similar looking specimen named E. calida on the ALA. and on the MovV Éctropis species' supporting PDF file. I have not found any suitable photos online of the underside of Ecrtropis species to compare the second image with.