No. 3 Officer's Quarters
The second room shows the quarters of another junior officer who has finished moving into his quarters. Because officers were considered gentlemen, they had to maintain a gentlemanly lifestyle. They employed servants from the ranks to maintain their rooms and equipment.
The rifle on the bed is a hunting rifle. It was not considered "gentlemanly" to kill enemies using a rifle through the loopholes, but only in hand-to-hand combat, or with swords and pistols. In the event of an attack, the loopholes at the back of the room would have been manned by common soldiers.