Those square-ish buttons aren't the jaws. You can see the open jaws under the cover plate
I wonder how hard it is to change jaws from small to large...
Some pre-production presses are out and at last we know how the jaws workIt looks like the squarish knobs are the screws holding the jaw assembly in place, and it looks like they were designed to be used by hand, no tools needed.
The knobs retain the jaws, but aren't really screws. What they retain is a round plate into which is cut half-moons with 90 degree separation. The cutouts are marked 223, 308, Small, and Large.
To change to a different case head size, your move the knobs outward to release them from retention. You rotate the knobs, and the attached plates, to the desired casehead size. When done, you push the knobs back toward the center...I believe they are spring loaded. Nothing to disassemble and no springs to lose. Everything is contained under that panel