Both Ricoh WG-6 and Samsung NX2000 have 20.0 MP resolution sensors but Ricoh WG-6's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Samsung NX2000's sensor is APS-C (23.5 x 15.7 mm ).
Since Samsung NX2000'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 Ricoh WG-6.
Below you can see the WG-6 and NX2000 sensor size comparison.
As seen above, Samsung NX2000 has a 13.1x Larger sensor area than Ricoh WG-6. 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.