Both FujiFilm Z700EXR and Leica V-Lux 20 have 12.0 MP resolution sensors but FujiFilm Z700EXR's sensor is 1/2-inch (6.4 x 4.8 mm ) and Leica V-Lux 20's sensor is 1/2.3-inch (6.08 x 4.56 mm ).
Since FujiFilm Z700EXR'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 Leica V-Lux 20.
Below you can see the Z700EXR and V-Lux 20 sensor size comparison.
As seen above, FujiFilm Z700EXR has a 1.1x Larger sensor area than Leica V-Lux 20. 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.