Thinner than FX mount = somewhat expected to allow for larger aperture glass. Very large throat diameter + a clear low light vibe in the ad plays along with the f/0.9 lens we've been hearing about. They also showcase a lens that is not what most would call tiny.
And either that mount's throat diameter is intergalactically big or it's a tiny width/height body -- the mount circle seems to be almost as tall as the entire body (sans EVF).
One would guess it's a novel control set as that rear LCD looks like it eats up most of the real estate.
Also: a non-tiny grip.
All decent calls, IMHO, though I'd prefer a 5D control set (thumb wheel especially) over a bigger screen.
- A