In some ways this makes perfect sense. Instead of saying it's penalizing un-mobile-friendly sites, you could say it's referencing mobile-friendly. But, paradox

In some ways this makes perfect sense. Instead of saying it's penalizing un-mobile-friendly sites, you could say it's referencing mobile-friendly. But, paradoxically, so many "mobile-friendly" sites are so much worse than their non-mobile selves.