Below you can see the front-view size comparison of the Fujifilm X-E2S and Panasonic S1R. The Fujifilm X-E2S is clearly the smaller of the two cameras. Its body is 20mm narrower, 35 mm shorter and 60 mm thinner than the Panasonic S1R.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.