What I gathered is that "mog" is from "amog" which means "alpha male of the group", which makes "mogging" being "out-alpha'd". Which isn't new, it goes back years if not decades to the "alpha male" trends through "pick-up artists" to modern-day incel/bro/manosphere/etc subcultures.

I know the author from about ten years ago and I'm not surprised he's into it. But also he's Dutch so it's probably used very much ironically / as a joke here.