If someone such as a writer or film director uses poetic licence, they break the usual rules of language or style, or they change the facts, in order to create a particular effect.
All that stuff about catching giant fish was just a bit of poetic licence.
poetic licence in British English
noun
justifiable departure from conventional rules of form, fact, logic, etc, as in poetry
Examples of 'poetic licence' in a sentence
poetic licence
This was more fantasy than poetic licence.
Times, Sunday Times (2013)
It seemed so obvious that the writers had taken a bit of poetic licence.
Times, Sunday Times (2007)
The smell she speaks of is either poetic licence or one of my senses is beginning to fail.