Below you can see the front-view size comparison of the Panasonic ZS100 and Olympus E-M1 II. The Panasonic ZS100 is clearly the smaller of the two cameras. Its body is 23mm narrower, 26 mm shorter and 23 mm thinner than the Olympus E-M1 II.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.