Just guessing, but it could be that they are claiming that 200 million unique videos are recommended on a given day, with the number of unique videos being a pr

Just guessing, but it could be that they are claiming that 200 million unique videos are recommended on a given day, with the number of unique videos being a proxy for how diverse they are. Perhaps before some of their recent changes, the number of unique videos was smaller. (Who can say for sure, though)