First off, let's look at the symbol for the EIC, because it's kind of amazing also: a heart split into quarters, a representation of the compass, with the company's initials stamped into the quadrants.
Dividing a heart into quarters and putting your mark on them? That's bold stuff. Almost as chilling as the Sherwin Williams "Cover the Earth" logo.
I wasn't able to find out why a 4 is on top of the heart, though I found some allusions to it being a government-mandated decision, a symbol to represent the Company of Merchant Adventurers of London, an even older and incredibly-awesomely-named confederation of companies with a charter to pillage and monopolize that dates back to the 1400's.
But as we said, besides the EIC there have been tons of symbols that represent business, religion, and government throughout history. Why is Bass Beer considered the first corporate symbol? Because it was the first one trademarked under the UK's innovative Trademark Registration Act of 1876.
A Bass Beer clerk whose name is lost to time waited overnight outside the registrar's office on New Year's Eve in order to be the first person in human history to publicly petition the government to protect a corporate symbol (at least in an above-board fashion.)
This idea catches fire of course, The U.S. has a working trademark act in place by 1881 (though interestingly enough, they began discussion of trademark protection in 1870. They just couldn't get it figured out till then)