Loch monster is seen differently (6)
I believe the answer is:
nessie
'loch monster' is the definition.
(I've seen this before)
'is seen differently' is the wordplay.
'differently' is an anagram indicator.
'is'+'seen'='isseen'
'isseen' is an anagram of 'NESSIE'.
(Other definitions for nessie that I've seen before include "Nickname for a Scottish monster" , "Supposed loch monster" , "Scots loch monster (colloq.)" .)