Below you can see the front-view size comparison of the Fujifilm Z900EXR and Olympus E-M10. The Fujifilm Z900EXR is clearly the smaller of the two cameras. Its body is 18mm narrower, 23 mm shorter and 28 mm thinner than the Olympus E-M10.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.