Panasonic G85 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor . On the other hand, Ricoh GXR Mount A12 has a
12.0MP APS-C (23.6 x 15.7 mm ) sized CMOS sensor .
Another difference between these two cameras is that Panasonic G85's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the G85 and GXR Mount A12 sensor size comparison.
As seen above, Ricoh GXR Mount A12 has a 1.6x Larger sensor area than Panasonic G85. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.