Box and single-side square are Poser primitives. OBZs located, un-packed to OBJs and UV-mapped. For each, invoke 'Reflection'. Delete the two subsidiary nodes. Add new node, 2d-textures, image map. Connect this back to reflection value. White reflects...

I don't know where/how that vertical black line got in, am hunting source. Also 'freckles' etc.

FWIW, Anime Girl is a budget ($), lowish-poly, FBX_7.4 VR-Chat Avatar which, to my surprise, 'plays nice' in Poser. Single rig, posable etc etc !! Apparently rigged in Blender, so have contacted author to ask *how* was done...

Now for brunch...