Superficial appearance even upset Queen Elizabeth (6)
I believe the answer is:
veneer
'superficial appearance' is the definition.
(I've seen this before)
'even upset queen elizabeth' is the wordplay.
'upset' indicates an anagram.
'queen elizabeth' becomes 'ER' (abbreviation for Elizabeth Regina).
'even' with letters rearranged gives 'vene'.
'vene'+'er'='VENEER'
(Other definitions for veneer that I've seen before include "Disguise" , "Thin layer of wood or plastic" , "Superficial coating" , "Outward respectability" , "A thin layer on the surface, often wood" .)