This chap looks like a German aristo on holiday, or an expatriate American playboy, or a European gigolo. Anm I mean these as compliments! That said, I would love to look like this chap when I’m his age. The “black thing” or “big dark thing” around his waist is (most likely) a sweater. I think. My only criticism is the lack of cuffs on his crisp white trousers. Otherwise, very well done.
Dont like this combination. The belt doesnt fit with the chemise and the fact that the trouser end up over the knuckle isnt stylish, but looks a little frouzy. If he wants to wear so much white things he needs to care about the accessoires a little more.