I'm afraid this didn't really answer my question. I wouldn't say that the income was from a New York source, as I was making sales from people from all over (i.e. I wasn't "employed" by any NY company). I am an artist and this was a small temporary popup event where I sold my artwork. I was there for two weeks and it was probably less than 10% of my total income from all sources.
And it was not income related to business previously carried on in the state, as it was my first time selling there.
So it does not seem like I need to file, but I'm not 100% sure?
