As I know, there is no proof of the fact, that it is a pic of Omi's boobs. It was published in several threads in several forums, but still no proofs.
In spite of that, there are other nice photos of Omi's tits:
Further more, some time ago Omi published her naked "Nami in the bathroom" photos , but they were"cloudy", you know. However magic of photoshop made "The Appearance of Pussy Before the People":