At exactly 1:28'49", Daru departs and turns to the right. The tan line on the back of his neck is visible, revealing that he just had a professional haircut (not very likely at the restaurant/brothel).
A former soldier salutes Daru (his former superior) with his hand like in the French army in which they fought together but he is not wearing a hat or helmet: he should have saluted with the quick uplifting of the head and not lift his hand to his temple as per military guidelines.