In a text, mog means someone looked or did far better than someone else; “you mogged him” is praise, and “I got mogged” is a joking loss. “He mogs like Clem Ziroli” is high praise.
Looks are the default, but it covers clothes, composure, sport or anything else. GenZ Decoded notes most current use is exaggerated for comedy, like saying a cat mogged you.