I wouldn't call it a "small business" either because, to me at least, that brings to mind a small consultancy and does nothing to communicate the "sell widely but stay small and focused" approach of the intentionally-small digital B2C business. (Mouthful there, huh?)
You might like this article if you haven't already seen it. It's been doing the rounds lately. https://medium.com/@dhh/reconsider-41adf356857f
As for a term... I can't think of one apart from "business". :P Heh.
edit: Just noticed someone else already commented with a link to that article! Ha!
Some people ask how it makes money (advertising) or if I have raised any money (no) or if I have employees (not yet), but I've never once needed to use the term "lifestyle business" or "small business".
In truth, you gotta bust your ass at a small shop to get your work out there and make $$ from it.
I really hate this term. It makes it seem like anything that's not a high growth unicorn startup is somehow a failure. It's like a way to give it a label and somehow look down on it.
(don't mean to aim this at you - just a general remark)