Compared social media approval, having sent back study (7)
I believe the answer is:
likened
'compared' is the definition.
('liken' can be a synonym of 'compare')
'social media approval having sent back study' is the wordplay.
'social media approval' becomes 'like'.
'having' is a charade indicator (letters next to each other).
'sent back' says the letters should be written in reverse.
'study' becomes 'den' (I've seen this before).
'den' backwards is 'ned'.
'like'+'ned'='LIKENED'
(Other definitions for likened that I've seen before include "Pointed out resemblance or compared" , "Equated" , "Resembled" .)