When using Streamer Mode to play, if you try to watch or save a highlight on your local pc, it will do so with a randomly given name (not even the one used during the game) instead of your very own account name.
Example: I play in a game with Streamer Mode on and it shows me as “IHoldW”, in the replays it will save with a name “Audica”, even though my account real name is “Afterstar”.