Reflect on purpose of shop rebuke (10)
I believe the answer is:
deliberate
'reflect on purpose' is the definition.
'deliberate' can be an answer for 'reflect' (deliberating is a kind of reflecting). I am unsure of the 'on purpose' bit.
'shop rebuke' is the wordplay.
'shop' becomes 'deli' (deli is a kind of shop).
'rebuke' becomes 'berate' (synonyms).
'deli'+'berate'='DELIBERATE'
'of' acts as a link.
(Other definitions for deliberate that I've seen before include "Done intentionally" , "Done consciously" , "debate" , "Taking careful thought" , "Ponder" .)