Oh my god Kei is sending so many mixed messages right now, on one hand we can read this as Kei telling Yokoe to just be herself and stop being so self conscious about everything, but then she went and took off the hair pin and covered Yokoe’s right eye once again, which I think symbolizes Yokoe’s willingness to hope for something to change in their relationship, and to be more honest with her feelings.
Put another way, Kei is telling Yokoe to not change. Maybe I’m reading too much into this but the whole scene kinda reminds me of Bloom Into You when Touko would always tell Yuu not to change.