Typical asian faces can't sell a product compare to a Ang Moh one.
It could be an inherited mentality from past generations and the racial diversity on this island. In a way, Ang Moh face is race neutral on most ads and has that perceived prestige; also it depends on the product being promoted.
Imagine if you have a Carlsberg commercial with a Chinese or a Keleng. What is the first instance that strikes your mind. Same goes for a malay.