Both Panasonic FX48 and FujiFilm S200EXR have 12.0 MP resolution sensors but Panasonic FX48's sensor is 1/2.3-inch (6.08 x 4.56 mm ) and FujiFilm S200EXR's sensor is 1/1.6-inch (8 x 6 mm ).
Since FujiFilm S200EXR'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 FX48.
Below you can see the FX48 and S200EXR sensor size comparison.
Sensor Size and Resolution Comparison image of Panasonic FX48 and FujiFilm S200EXR Cameras
As seen above, FujiFilm S200EXR has a 1.7x Larger sensor area than Panasonic FX48. 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.