Compare: 素 vs 素

どうやら、さっきのは演技ではなく、素(す)だったらしい。

It seems like that she wasn't acting back then; they were her real feelings.

生粋のお嬢様だからな。残念ながら悪戯(いたずら)とかじゃなくてあれで素(す)だ。

She's pure bred blue-blood you see. Unfortunately that's no sort of put-on but her natural self.