Yeah. I treat one-man small business serving mainly one big client to be comparable. On paper it's B2B, in reality it's working for the client and if the client is small business' main source of income, it's pretty much an employment.
Differences, in Poland at least, are that small business owner in this scenario is not protected by employment laws (3-months notice layoff, max 3 months salary-equal damages liability etc) and uses company's (EU)VAT registration number instead of personal social security number equivalent (PESEL number). It eases abroad contract agreements, invoicing and allows serving more clients easily. Company existence can also be validated on EU VIES[1] website quickly.
In the visa case, I have of course used the "paper" phrasing as in reality I was, and am, only employed by my own small business.
Probably you answered an officer (or airline worker) that you were gonna "work" there, not just visit your employer for an event?