It looks like the LG H840 has 3 GB of RAM and 32 GB of internal memory, and sports a 5.3-inch Quad HD (1440 x 2560 pixels) display - slightly smaller than the screen of the LG G5 (likely a 5.5-inch one). Sure enough, this doesn't make the H840 less advanced than the G5. What does make it belong to an inferior class is the processor, which appears to be Qualcomm's mid-range octa-core Snapdragon 625 - certainly no match for the top-of-the-line Snapdragon 820 that's expected to power the G5.
The really weird part about all this is that, according to the listing (seen on the right), this upcoming handset runs Android 4.4 KitKat - but that is, almost certainly, a mistake of some sorts, as it's unlikely for the device to run anything else than Android 6.0 Marshmallow.
By the looks of it, the H840 may be a Lite variant of the LG G5 flagship, akin to what the LG G4 Beat (aka G4s) was compared to the LG G4. We've no idea if the LG H840 will be announced on the same day as the G5, but we're going to let you know if it does.
source: WinFuture (translated)