Panasonic G85 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor . On the other hand, Olympus E-M1X has a
20.0MP Four Thirds (17.4 x 13 mm ) sized CMOS sensor and features Dual TruePic VIII processor.
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 E-M1X sensor size comparison.
Panasonic G85 and Olympus E-M1X have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.