As a desperate ploy to get people to pay attention to the safety demonstrations on aircraft, cabin crew frequently say that the instructions on their plane may be different to those that you're used to hearing elsewhere.
Have you ever encountered an airline which has invented its own, unique brace position? Or produced a peculiar alternative to the toggle device that inflates the average lifejacket?
My hunch - and it's no more than a hunch - is that there are probably legal and regulatory requirements which pretty much standardise the whole safety procedure. BA, for instance, couldn't unilaterally decide that they would dispense with oxygen masks or require passengers to pull them out of a headrest rather than wait for them to drop down from the ceiling.
So when you're next told that your aircraft may be different, why don't you stand up and ask the stewardess exactly how? You'd have my full support.