Isn't it quite a leap to go from single image to usable 3DGS model? The editing part seems relatively minor step afterwards. I thought that 3DGS typically required multiple viewpoints, like photogrammetry.
It says it uses a mirror image to do a Gaussian splat. How does that infer any kind of 3D geometry? An image and its mirror are explainable by a simple plane and that's probably what the splat will converge to if given only those 2 images.