Thank you for your input. Yes. According to https://www.dhs.gov/immigration-statistics/lawful-permanent-residents/ImmigrantCOA, my friend entered on the AS7 Spouses of AS6 , so that's an immigrant visa.
But:
According to the question explanation offered by USCIS I-90 online form, that is not:
"Did you enter the U.S. on an immigrant visa?
Immigrant visas are processed and issued by U.S. consulates in foreign countries. If you have obtained a green card by applying for permanent resident status after entering the United States, you are not entering on an immigrant visa."
According to the explanation, because my friend was admitted into USA based on the asylee dependent status in 2011 (I saw that stamp in his passport), then obtained his permanent residence in 2012 (residence since 2012), he is NOT entering on an immigrant visa.
That why I think it's so confusing.