The fact they spin and the bits interact gravitationally makes them symmetric. There are almost certainly some asymmetric galaxies as we know galaxies collide and they will be asymmetric for a bit afterwards, but the spinning and fiction of gravity will make them symmetric again fairly quickly on galactic time scales.
Laws aren’t better than theories; they are generally statements about a narrow range of phenomena which can be expressed mathematically while a theory covers a wide range of phenomena. For example, theory explains the origin of all conservation laws in physics as being the result of symmetry. Each law covers a specific thing (i.e. conservation of momentum) while the theory covers all conserved quantities.
Most of that is the helium dilution refrigerator. Most electronic quits work at near absolute zero, so all of what you see here is wiring for the quantum computer (all those co-ax cables) and the equipment needed to manipulate the helium mixture to cool things down (you need the right mixture of helium isotopes because they boil at different temperatures so boiling away one isotope allows the remaining isotope to get even colder).