It's basically the same as if you go to a trade show in the US. All the salespeople are trying to figure out which visitors are CEOs and, hence, worth their time, and which ones are just curious amateurs.
Maybe Google "Thuan Pham" - the Vietnamese Uber ex-CTO. He's doing it so well that even for us westerners it's easy to see that he's in a position of power. He isn't going to be charged tourist pricing due to his skin color (which is normal for Vietnamese). He's going to be charged tourist pricing because of his behavior which indicates that he's mind-boggingly rich and powerful.
So for everyday living, $80mio in Vietnam is going to feel like $8bio in the US (because steak in a restaurant is $50 instead of $0.5 for a 100x multiplier in living costs).
Very little to do with skin color, it's just most often the biggest giveaway that the buyer is a foreigner.
This is strictly personal, but where I grew up with mostly light skinned people... showing up after winter holidays with a dark tan made you look so hot and so rich! Did anyone else feel the same? It carries into my life as an adult. :)