Panasonic LX100 has a 13.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine processor. On the other hand, Panasonic LX100 II has a 17.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine processor.
Below you can see the LX100 and LX100 II sensor size comparison.
Panasonic LX100 and Panasonic LX100 II have 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 Panasonic LX100 has 32% larger pixel area compared to Panasonic LX100 II, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.