Slogan here shows big heart protecting society (6,7)
I believe the answer is:
bumper sticker
'slogan here' is the definition.
(a bumper sticker may feature a slogan)
'big heart protecting society' is the wordplay.
I cannot really see how this works, but
'big' could be 'bumper' (I've seen this before) and 'bumper' is found in the answer.
'heart' could be 'ticker' (synonyms) and 'ticker' is located in the answer.
'society' could be 's' (common abbreviation in names of organisations) and 's' is found in the answer.
No letters remain.
This may be the basis of clue (or it may be nonsense).
'shows' is the link.
(Another definition for bumper sticker that I've seen is " Slogan on car".)