Andrea has made a video about the leaked images of the Fujifilm GFX100RF and has made an approximate size comparison between the Fujifilm GFX100RF, Fujifilm X-Pro3 and Leica Q3.
Of course these are very approximate size comparisons, so don’t take them as 100% accurate. But if the size comparison is accurate, then the GFX100RF would look about as wide as the X-Pro3 and Leica Q3, just a little bit higher.
But the more interesting thing is the lens. The one on the Fujifilm GFX100RF looks quite compact as opposed to the lens on the Leica Q3, which protrudes quite a bit from the camera body. This could ultimately make the GFX100RF a more pocketable solution than the Leica Q3, even though it has a sensor about 70% larger than the Leica Q3.
Dimensions
Also, FR-reader Matt compared the size of the Fujifilm GFX100RF to other cameras by aligning the width of the hotshot as seen in this image.
According to this, the size of the GFX100RF should be around 135mm (W) x 94mm (H).
Here you have it guys, the first image of the Fujifilm GFX100RF front view with lens (top and backside image here).
Size seems quite reasonably for me, and the lens looks very compact compared to the rather long lens of the Leica Q3.
Interestingly there is still the viewfinder switch we have on the X-Pro and X100 line, even though the Fujifilm GFX100RF has only an electronic viewfinder. So I guess it will have some other function.