It's funny how this is basically conceptual lossy compression. The pixels aren't close to being exactly what they were in the reference image. But it doesn't matter because I'm notice going to notice the mildly different pattern on a tiger, or skin texture.

It's important to gauge the value of the result - is it producing something that looks nice or something useful.

It just looks nice. Once you downsample, you cannot accurately upsample again. If the upsampled image looks real to you, and if you would downsample that again you get the same downsampled image, then you did the best you could.