On the whole Millennials are the most liberal generation in American history, but when you wade into the specifics you see certain differences in what counts as liberal for them:
Attitudes toward big business are also interesting. Anti-Wall Street sentiments are common, but on the other hand Millennials' lives revolve around things made by their favorite corporations – phones, video games, social media platforms – and many idolize entrepreneurs like Elon Musk. The comparatively low support for abortion relates to the common ambivalence about "feminism," which for many evokes "women's libbers" of the 70s rather than anything in the contemporary world. I have been very much struck that hardly any young people think having Hillary become president would be some sort of historical event.
Attitudes toward the poor are also worth considering in depth. Much of the economic politics of the past decade has been about the increasing divide between the 1% and the 99%. When that is your frame of reference, you can end up thinking that all non-rich people face grim obstacles, which makes you wonder why middle class people manage nonetheless to take care of their families while poor people can't. The overall culture of many young people, especially in college, emphasizes how hard everyone has to work to get ahead, and people who feel crushed by their own struggles are not likely to think poor people have it that much worse. There is also a fair amount of scorn for poor folks (especially poor white folks) who are anti-gay, anti-trans, pro-Trump or what have you. This doesn't mean that Millennials are as a group anti-poor, just that even though they proclaim themselves very liberal their support for programs focused specifically on poor people is around the national average.