Below you can see the front-view size comparison of the Panasonic ZS100 and Olympus E-M5 II. The Panasonic ZS100 is clearly the smaller of the two cameras. Its body is 13mm narrower, 20 mm shorter and 1 mm thinner than the Olympus E-M5 II.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.