Below you can see the front-view size comparison of the Panasonic ZS100 and Nikon 1 J5. The Nikon 1 J5 is clearly the smaller of the two cameras. Its body is 13 mm narrower, 5 mm shorter and 12 mm thinner than the Panasonic ZS100.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.