From what I understood of the video: Riho, Kanon and Mizuki went for the cute image while Erina went for the cool image (or was asked by the staff to go for a cool image?) Erina really looked good in this episode.

When the 5 nominees from the audition were announced, I cheered for Erina (and Riho) and I disliked Kanon.

But now that they had their first stage experience, I feel the other way around. I don't remember seeing Erina look so scared in the auditions.