Picture of old king wearing hat (8)
I believe the answer is:
panorama
'picture' is the definition.
(I know that panorama is a type of picture)
'old king wearing hat' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'king' becomes 'R' (abbreviation for rex, king in Latin).
'wearing' indicates putting letters inside.
'hat' becomes 'panama' (panama is a kind of hat).
'o'+'r'='or'
'or' put within 'panama' is 'PANORAMA'.
'of' acts as a link.
(Other definitions for panorama that I've seen before include "Wide unbroken view" , "Current affairs programme" , "Wide view - TV programme" , "Wide-angle view" , "long-running programme" .)