Gerard ter Borch situates the quiet, reflective activity of letter-writing in the traditionally boisterous environment of the guard room. Card-playing was a favorite activity of lovers, and the ace of hearts on the floor in the foreground suggests that the letter being written is an amorous one. The shards of clay pipe scattered around the card refer both to merrymaking activities usual in such a room, and to frustrations the letter-writer is having in expressing his romantic feelings.