Actually, mini rex crosses usually do not have fur ANYTHING like a mini rex does. They usually have normal fur, just like any other rabbit. However, netherland dwarfs have pretty soft fur for a normal furred rabbit (it is a bit longer and finer), so a netherland cross could certainly feel extra soft.
Edison, though, looks like a pure mini rex to me. Very typical mini rex features. Technically, if it was sold to you as a "dwarf" that is true. "Dwarf" can imply any breed that typically has the dwarfing gene. That includes netherland dwarf, dwarf hotot, mini rex, jersey wooly, american fuzzy lop, holland lop, some lines of polish, some lines of dutch, and even some lines of mini lop (which actually can weight around 6 1/2 pounds). Even if he was a netherland dwarf cross, if he inherited the dwarfing gene from the netherland parent, he could still have been a "dwarf." That is why pet shops use that term. It is extremelly broad. All it means is that the rabbit either has the dwarfing gene itself (even if it is a crossbreed) or that it is a breed that typically has the dwarfing gene.