It has everything to do with geographic proximity. India is a union state that includes people of many races. You have African-looking Dravidians in South India, with very dark skin, and almost curly / kinky hair. To the East, there are Bengalis who have rounder eyes, then to the far east, you have Tai ethnics in Assam, Nagaland, Sikkim who look more like Burmese and Thais and Laotians. Then you have more Caucasian looking Punjabis and northern Rajputs. So with that said, one has to understand the differences in Indian phenotype. There is no such thing as an "Indian phenotype" actually. Since there are many races in India.
You would have to differentiate what type of Indian ethnic. Because an Indian from Sikkim will DEFINITELY not look like a an Indian from Kashmiri. They are totally different races. One, the former is of the Mongloid Race, the other is of the Caucasian race.