Superficial attractiveness demands explanation (5)
I believe the answer is:
gloss
I believe this is a double definition.
'superficial attractiveness' is the first definition.
(gloss can mean an attractive facade)
'explanation' is the second definition.
(gloss is a kind of explanation)
'demands' is the link.
(Other definitions for gloss that I've seen before include "Show" , "phrase's explanation" , "Provide explanations" , "Very shiny finish" , "Shiny type of paint" .)