1. The LG G3 is not a small phone
Let's just get this out of the way. If you're looking for a petite smartphone, the LG G3 isn't it. It's got a 5.5-inch display. (Last year's LG G2 had a 5.2-inch display, and the Samsung Galaxy Note 3 is 5.7 inches, by way of comparison.) It's nearly a full centimeter taller than its predecessor, just over 4 mm wider, but just about as thick. (You can find the complete LG G3 specs here.)
It'll still fit in your pocket, of course, but you'll know it's there. And LG's got some pretty innovative features that help mitigate the phone's size. (We'll get to those in a little bit.)
So, yeah. It's a tall, thin phone.
And that's OK, because ...