I chose tone, storytelling/emotion, and genre.
Tone - yes, though not sufficient on its own. While I can appreciate good singers that don't have a tone I like, they won't be a snowflake. But even if they do have a tone I like, there needs to be more to make me like them (such as storytelling/emotion and genre/style)
Pitch - sort of, there does need to be a decent ability to sing on pitch for me to like someone, but other aspects tend to play a much stronger role in whether or not I like them. And I tend to be more lenient for singers I enjoy.
Vocal tricks - no, though I can definitely appreciate it
Storytelling/emotion - yes, delivery is super super important to me. I need to be able to feel things from what they're singing, regardless of whether they have super great technical abilities or not.
Arrangements - no, though I can appreciate it and if they are in the realm of possible snowflakes due to other aspects, it can be an asset if done well
Instrumentation - no
Personality - sort of, I'm not going to like someone who's a jerk, but otherwise an appealing personality is just an asset.
Looks - no
Genre - yes, I need to like their style. If someone is in my preferred genre, it is much more likely they will become a snowflake. But for my less "typical" snowflakes, I still like their style. And there are some styles that will never be something I prefer
Gender - no, though it may contribute to tone.
Age - no