Both Nikon L31 and Panasonic TS30 have 16.0 MP resolution sensors but Nikon L31's sensor is 1/2.3' (6.17 x 4.55 mm ) and Panasonic TS30's sensor is (1/2.3 ).
Since Nikon L31'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 Panasonic TS30.
Below you can see the L31 and TS30 sensor size comparison.
As seen above, Nikon L31 has a infx Larger sensor area than Panasonic TS30. 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.