Small, the head photographer (7)
I believe the answer is:
snapper
'photographer' is the definition.
(I've seen this before)
'small the head' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'the head' becomes 'napper' (informal term for someone's head).
's'+'napper'='SNAPPER'
(Other definitions for snapper that I've seen before include "sharp-toothed fish" , "Person photographing" , "Fish; marine turtle" , "(Often red) food fish" , "Fish; photographer" .)