Poster of British lumberjack (7)
I believe the answer is:
blogger
'poster' is the definition.
(someone who posts on a blog)
'british lumberjack' is the wordplay.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'lumberjack' becomes 'logger' (logger is a kind of lumberjack).
'b'+'logger'='BLOGGER'
'of' is the link.
(Other definitions for blogger that I've seen before include "like Guido Fawkes?" , "Modern writer" , "Online journalist" , "One writes a journal on the internet" , "Contemporary diarist" .)