Both Olympus TG-3 and Panasonic G85 have 16.0 MP resolution sensors but Olympus TG-3's sensor is 1/2.3" (6.17 x 4.55 mm ) and Panasonic G85's sensor is Four Thirds (17.3 x 13 mm ).
Since Panasonic G85's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Olympus TG-3.
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 moire occurring in certain scenes.
Below you can see the TG-3 and G85 sensor size comparison.
As seen above, Panasonic G85 has a 8.0x Larger sensor area than Olympus TG-3. 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.