This seems closest to how I'd describe it. It also (as with all phones but seemingly even more so with the G4 in my experience) varies wildly depending on what you're doing. Using the camera or editing pics (even the Gallery uses a ton of juice) and the battery will be pretty bad. That isn't a shocker given that cameras usually chew up battery, plus the quality of the camera and of the screen on the G4, but it's more severe than I've ever experienced.
It isn't only the camera and SoT, though. I've paid particularly close attention to my battery behavior since I got the G4 in mid-June. My sense of its discharge rates are that they can vary noticeably from one day to the next, even if I don't use the camera or view/edit pics, and use seems otherwise very similar. While this is probably tied to using an app or two more than others one day compared to the next, it isn't something I've pinned down.
Over more than 5 months with the G4, I'm still left scratching my head fairly often as to why battery is so different this day compared to that day with similar SoT and overall usage.
The bottom line I've finally landed on, in my most humble opinion, is that the calibration, and probably optimization, of the G4 battery is not ideal. While battery discharge is often pretty good, it is also unreliable. Now, the first thing keeps the second thing from being a deal breaker. Even when I have days when the battery life seems less, it's still OK.
I just never have felt that I got it "right" with tweaks and such on the G4. I've not felt that way with a phone before. Even if it was only the "best I can do," I've gotten to as point I felt I had maximized use for my needs and preferences on any particular phone. The G4 always feels like it's somehow wasting some of its power.
All of that assumes you actually use your phone. If I set iot on a table and didn't light the screen, I think the thing might need a charge in July. Standby time is excellent.