When photo shows jelly (5)
I believe the answer is:
aspic
'jelly' is the definition.
(I know that aspic is a type of jelly)
'when photo' is the wordplay.
'when' becomes 'as' (eg 'when I walked' means 'as I walked').
'photo' becomes 'pic' (short for picture).
'as'+'pic'='ASPIC'
'shows' acts as a link.
(Other definitions for aspic that I've seen before include "Savoury jelly for coating meat, eggs etc" , "Clear meat or fish jelly" , "Ending of Marlowe's thriller" , "Clear savoury jelly" , "Savoury jelly for meat or vegetable" .)