Crossword Genius

Sensitive types some say but they are all unique (10)

Ross

I believe the answer is:

snowflakes

I'm a little stuck... Click here to teach me more about this clue!

'sensitive types' is the definition.
Although both the answer and definition are plural nouns, I can't understand how they can define each other.

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for snowflakes that I've seen before include "Those are cold" , "Spineless sorts" .)

I've seen this clue in The Guardian.
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