A man stripped to his underwear
Are the pants worn by a man or a woman?
If they’re worn by a woman, they’re underpants, or don. Women commonly wore don as their only leg coverings.
If the pants are worn by a man, does he look underdressed?
If he’s underdressed, the white pants are also don.
If he looks fully dressed, the pants are probably a white version of caksir, the standard loose-fitting pants of the Ottoman world.