This update adds a new "mirror bundle pack" as an assetbundle that now has a total of 3 shapes: the original oval shape, a square mirror and a mirror shaped as a circle. Each of the three mirrors has a 1080 pixel (hd) and 2160 pixel (4k) version.
There is also a new demo scene, Reflections Demo 2, which includes selector buttons to quickly switch to each of the three shapes. (See last image below).