Both Samsung WB250F and Samsung WB150F have 1/2.3-inch sized 14.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the WB250F and WB150F sensor size comparison.
Sensor Size and Resolution Comparison image of Samsung WB250F and Samsung WB150F Cameras
Samsung WB250F and Samsung WB150F have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Samsung WB250F has 14% larger pixel area compared to Samsung WB150F, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Samsung WB250F
or the
Samsung WB150F ,
including hyperfocal distance.