Can We Join You, Zara Unnie??!!?

In the Korean comments

One comment offers a specific rewatch prompt, saying, in translation, “Yuna waving her scarf in the back is so cute—and Jiwoo sitting down at the end is cute too.” Another describes the clip’s personality switch as, in translation, “It feels like A-na and Stella swapped souls.”

What the words mean

언니 (eonni, written “unnie” in the title) literally means an older sister when used by a female speaker. Here it is a casual, affectionate way of addressing Zara as a familiar older woman, not a claim that she is anyone’s sibling.