Below you can see the front-view size comparison of the Fujifilm X-A3 and Fujifilm SL1000. The Fujifilm X-A3 is clearly the smaller of the two cameras. Its body is 6mm narrower, 22 mm shorter and 83 mm thinner than the Fujifilm SL1000.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.