Lots of business and org names are acronyms, but it really stands out to me how most of the early ones are short. I guess in the age of excessively-long UUCP addresses, it was immediately obvious that short domain names would be preferable to longer ones.
The two letter domain names really stuck out to me. I had a boss ask me back in the early 2000's to register a two letter domain and I was surprised to find that Network Solutions would no longer do that. I didn't spend much time on it so maybe another registrar would but as far as I can remember two letter domains just weren't an option at the point. I guess TI, GE and HP were smart to grab them when they could!
There used to be an old site that visualized the two- and three-letter domain name space as two- and three-dimensional grids. It was neat seeing the pixels fill in over time.