Below you can see the front-view size comparison of the Olympus E-PL9 and Fujifilm GFX 50S. The Olympus E-PL9 is clearly the smaller of the two cameras. Its body is 31mm narrower, 26 mm shorter and 52 mm thinner than the Fujifilm GFX 50S.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.