I mean in the amount of energy it has and in its size. That which is observable is apparently only a sub-universe. It seems to be limited only by physical laws, but even those laws could be different in other sub-universes.
I don't know about any differences. Particle physicists don't have much of an opinion on gravity and on uniting gravity with the other forces.
A proton and neutron can still have three quarks each with some of them being matter quarks and others being antimatter quarks. The strong and weak forces can be manifestations of gravity and electromagnetism at short scales, and electromagnetism could be a manifestation of gravity and anti-gravity, but particle physicists generally do not concern themselves with such ideas.
I can look at this object and suppose the center or ring is antimatter or matter and the difference apparently mostly involves changing the relevant dominant bipolar gravity wavelength. Add a half-wavelength to the distance from matter and the matter's gravitational effect becomes that of distant antimatter, in one variation of a bipolar gravity theory.