I wouldn't denigrate Intel or Low Tech Magazine as greenwashers. They have put more resources into actual environmental efficiency than into advertising their efficiency. But they have both made some decisions that prioritize conspicuousness over effectiveness.

I find it at least a bit difficult to believe that either Low Tech Magazine or Gauthier Roussilhe simply don't know any better about optimizing images for compactness at this point. Surely someone has tweeted advice to them even if they didn't originally know. Maybe that's my own failure of imagination.