Both Samsung WB800F and Sony NEX-5T have 16.0 MP resolution sensors but Samsung WB800F's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Sony NEX-5T's sensor is APS-C (23.4 x 15.6 mm ).
Since Sony NEX-5T'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 Samsung WB800F.
Below you can see the WB800F and NEX-5T sensor size comparison.
As seen above, Sony NEX-5T has a 13.0x Larger sensor area than Samsung WB800F. 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.