The comment didn't claim it was a startup, but besides that: there's a number of successful startups that have began life as "side hustles"

whats the startup purity test?

By strict definition it is a startup. By practical definition, this is just a small business. Startups typically intend to scale.

In my mind, I think of it as the “farmers market test”

* small or hobby business - you personally make and sell your items at the local farmer market.

* startup - you might sell at the farmer market, but you also have a factory that distributes and ships.