Well, I've always been fascinated with Red Velvet's dynamics. The contrast and the similarity how they are their own family roles to the roles they ought to have upon being placed on the same group.

• The natural way Irene fell to the role of being the Eldest and the Leader of the group, probably because of the similar upbringing since she's also the unnie in their home, but still a little different since afaik, she only has one sister
• The way the 94-liners are both in awe and looks up towards how amazing Irene is being their (and the group's) unnie and the contrasting way they try to fit into the "unnie" role:
  • Seulgi, being the dongseng of an older brother at home, became the unnie that is playful and reliable.
  • Wendy, being the dongseng of an older sister at home, became the unnie that can be naggy but also nurturing.
• The different way the maknae reacts towards having unnies despite being the unnies in their own hosehold:
  • Joy, who loves to revels being the dongseng but doesn't forget to unnies. The first to tease the 94-liners but also the first to cheer them on. Who may or may not feel a little bit hesitant to indulge Irene's unnie-ness because she somehow feels embarrassed doing so. She also loves to dote on Yeri because it's still in her nature to be an unnie.
  • Yeri, who like cringe in everything her unnies do for her but always so proud of them. She probably secretly loves them doting on her and feels the most proud when her unnies cheer on her. Maybe, she sometimes feel a teeny bit jealous how her Joy-unnie can easily show how she adores her unnies but still feel secured that they probably know it that she feels the most secure and safest when she's with them.