I always thought it was a combination of both looks and personality. Maybe I was wrong.
While it’s been a while since I’ve seen the original anything, I thought it said the queen was beautiful (and so “fair”) visually, but she had a cold heart as she got older and more vain (and so was no longer “fair” in personality).
There’s an NPR episode of Code Switch on the subject:
https://www.npr.org/sections/codeswitch/2014/05/16/313154674/mirror-mirror-does-fairest-mean-most-beautiful-or-most-white
I always thought it was a combination of both looks and personality. Maybe I was wrong.
While it’s been a while since I’ve seen the original anything, I thought it said the queen was beautiful (and so “fair”) visually, but she had a cold heart as she got older and more vain (and so was no longer “fair” in personality).