You can say that I value someone's appearance (or look) over intelligence (or brain)
But how to say that in a general way?
In my country we would translate as "appearance vs substance". Is there a correspondent idiomatic word in English?
A common phrase is "form over function." It's not usually used to relate to people, though, but the values of those who design things:
The architect of this house clearly valued form over function.
This would mean the house was beautiful, but impractical to use for whatever reason.