The invitation, with "See the Great, Feel the Great" written in leather, was sent to media outlets and this may suggest that the phone will come with a leather back, or something of the sort. It will at least have some nice leather covers. 

We are quite sure that the flagship phone doesn’t come with the Snapdragon 808 SoC as rumoured by some tech sites. But there is a catch - LG usually has a few different SKUs, so we might see various hardware configurations.

The one snapped at the GFXBench data base data base has Android 5.1, 2560x1440 5.5 inch screen, hexa-core CPU at 1.8GHz from Qualcomm, probably the Snapdragon 808, as well as Adreno 418 graphics. The phone has 2.8GB of memory, 23GB of available storage (3GB RAM and 32GB or total storage), 15-megapixel rear and 7-megapixel selfie camera.  

If we were to bet, we would suggest than the full blown LG G4 comes with the faster Snapdragon 810 in order to stand a chance against Samsung's Galaxy S6 series and HTC One M9 flagship phones.

The event is set for April 28th^, with availability expected shortly thereafter.