The answer to this question depends on where the audience lives for a long time and what the people around them look like.
According to psychological research, people are more likely to notice places where other people are different from themselves or their surroundings. When we live in China or other countries in East Asia for a long time, the people around us are Asians with East Asian faces, and when we appear in front of an Asian-European mixed child, our subconscious will first notice that he is different from us, that is, the places on his face that have European and American characteristics, so we will think that he is a mixed race with a European and American face, and even think that he is a foreigner.
In the same way, when we live in Europe and the United States for a long time, when most of the people around us are European and American whites, when we see an Asian-European mixed child, we will first notice that his face is different from the characteristics of the local white people, that is, Asians, so we will feel that this mixed race has an "Asian face", and even think that he is a Chinese or Japanese or Korean.
This is also why the three countries of China, Japan, South Korea and East Asia can easily distinguish each other in terms of appearance, while Europeans and Americans look at us exactly the same.
Similarly, if they did not live in Europe and the United States, It is difficult for East Asians to distinguish between The British, the Germans, the Swedes, and so on, although in fact they have a clear and obvious difference between them.