The leak actually comes from the Google Play Store, as it was hidden inside the Play Store app on Android, where Android Authority managed to find it. The leak is actually a banner that was probably going to go live at the event, but it clearly shows the entire lineup next to each other.
While we still don't have the detailed look, the banner shows the entire lineup from the back with specific camera island design, and two colors that will be available, Indigo and Moonstone. The banner also shows the promotion, a $50 off that will probably be offered at the launch.