The Countess sees Cherubino 's letter about joining the army , and she notices that the Count was obviously in such a hurry that he forgot to seal it with his signet ring ( which was necessary to make it an official document ) . At this time , the Countess sees Cherubino 's military commission , and notes that the Count was in such a hurry that he forgot to seal it with his signet ring ( which was necessary to make it an official document ) .