Below you can see the front view size comparison of Sony RX10 II and Panasonic G9. Sony RX10 II is 8mm narrower and 9mm shorter than Panasonic G9 but it is also 10mm thicker.
Sony RX10 II vs Panasonic G9 - Front View
Sony RX10 II vs Panasonic G9 - Top View
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.
Camera Size Comparison
Select Two Cameras for Size Comparison