Their symbolism and many aspects of their modus operandi were very similar to each other. A "holy book" a founding figure, paternalism, revolutionism, populism, ideology, enemies, uniforms, monologues, youth groups. By 1948, Hitler in 1938 looked like a caricature of a dictator. Orwell was incredibly sharp in seeing the commonalities between that generation of dictators and seeing it as early as he did. The relationships between the ideology and control, the axis of cultural control. I think starting with a literal parody was useful approach. But, in 1948 he was describing something that had happened and had largely already (though he didn't know it then) reached its peak. Even though he was clearly skeptical, critical and wary of authoritarianism going back to his days in the Spanish civil war a decade earlier, he didn't have that sharp, simp effective vocabulary that exposes and characterizes the thing until it had passed its peak.
The authoritarian states that did survive were/are tended to be descendants of those 1920s-1940s systems, often in cultural backwaters. Orwell's terms hold up pretty well for describing North Korea, Baathist Iraq/Syria, Nasarist Egypt, Maoist China, Central Asain Former Soviet Countries or Ghadafi. Remarkably well.
My point (poorly made) is that whatever authoritarianism is/will rise out of this data gathering, corporate-government surveillance euthorotarianism model is only now taking shape. It hasn't peaked yet. It isn't fully formed. We don't yet know what its central themes are or how it works. We don't know how it maintains power or dampens opposition. It may never even come. I hope it won't.
We won't have the right vocabulary until its too late. The Romans were on the lookout for potential Kings. They didn't know to watch out for Caesars.
I can make some guesses but I really don't know what the symbols of this new tyranny are. I don't know how to parody it.