I recently came upon with a sentence:
In her office at Oxford University Press, Paton was drafting a brand new entry for the Oxford English Dictionary. Also in her in-tray when I visited were the millennial-tinged usage of “snowflake”, which she had hunted down to a Christian text from 1983 (“You are a snowflake. There are no two of you alike”), and new shadings of the compound “self-made woman”.
I think "millennial" here refer to people of Generation Y. What I fail to understand is why the saying "You are a snowflake. There are no two of you alike" is tinged with millennial features? Does it reflect something specially linked with Generation Y?