I'm on a social media platform that provides the bigger picture (4)
I believe the answer is:
imax
'provides the bigger picture' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'i'm on a social media platform' is the wordplay.
'on' says to put letters next to each other (in a down clue, letters appear on others).
'a social media platform' becomes 'ax' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'im'+'ax'='IMAX'
'that' acts as a link.
Can you help me to learn more?
(Another definition for imax that I've seen is " large-screen cinema".)