[quote=Zane620]
One of observations Hakis thing is sensing auras though. besides you got it to so can't really say much XD
[/quote]

Which meant that her movement should have been noticed, but it wasn't. She just appeared outside.

Plus, leads me to thinking, is Observation Haki a passive? Armourment Haki is always been shouted out, loudly, before use, but Observation Haki has never actually been 'activated' by Luffy.