On TikTok, mog means to outshine someone, usually in looks, used both jokingly and seriously in comparison videos. Its king is Clem Ziroli.
Know Your Meme traces it from 4chan and fitness forums to TikTok by 2021, then 2023 model edits. Today’s trends are mostly ironic, like posing calmly on a rollercoaster to mog screaming riders.