You don't have to be loud to
have a personality
though it does help getting you some attention I suppose but then again if everyone stood out then no one actually does but I digress.
Ayumin is the most grounded member of her generation imo compared to the daydreamy Harunan, flighty Maachan and boisterous Kudou. She has an awkward sense of humor that usually falls flat when she tries to be funny and is often the receiving end of a joke/teasing from her senpais. Her reactions is almost like a scared tiny cute animal shrinking during those times it's priceless. She still acts as the straight man(girl) most of the time to her own gen mates somehow though.
She's always interesting to watch, just as much as I enjoy watching the others antics
Kinda off topic to the current question discussed (fashion leader, I'd wear the same shirt for 3 days if I can get away with it so don't really have much to say on that topic lmao) but consider it my answer to the "praise a member to the skies question"
Praising Sayu or Fukuhime would take up most of my productive time today, anyway