That's not a portrait, it's known as a candid.
:thumbdown: Based on what assumption? I can tell a few stories about this person based on the photo. They may all be wrong but I still can and that is enough, to me, to qualify it as a portrait.
The white balance is off quite a bit which is why his skin has such a strong orangeish cast. The camera being set to sunlight for the white balance, even though the light source is actually tungsten/incansdescent, gives the orangeish cast to a photo.