When the Admiral Van Leer came in the hall and said his sentence to Sinon, She standed up quite fast because of the authority voice.
Sinon Yuki: Sinon Yuki ready for duty!! with energy.
When she looked in the direction of the voice and saw a man with a high rank. Sinon did not know how to act. So she apologized.
Sinon Yuki: Oh euh.. Excuse me sir to act like if I was at home! Sir! I was waiting for the others to let them know who I am... You see, It is important for me and for my future within the 46th and as I see, I think it will not happen...
She bent down to express a sincere apology. In her voice and moves, we can perceive she was educated as a Kusarian and not as a Libertarian. After she bent down, she did a salute to the man like all soldier would do toward a higher rank.