Going by the "How it works" section of the GitHub page (not the web site), it appears to be both whitelists and blacklists, plus heuristics for unknown brands to flag the keyboard-mash brands that are almost certainly junk.

I wonder why in the age of LLMs these brand names continue to exist. I just prompted deepseek in Chinese to give me some novel brand names in english for a lighted dog collar (something I recently searched for and saw the crazy brands), and it gave me a bunch of plausible sounding names. Granted, not particular inspired, but names that an English speaker would recognize as reasonable brand names