Yeah, this can be confusing. This is referring to the "growl" effect in complete vocal technique. Imagine Christina Aguilera making a dramatic car engine growl when you kick down the gas pedal. I think this is roughly what this is about.
I wondered about the same thing. Not an answer, but my guess would be that it's just a new package and they hoped someone picked it up by accident?
In that case, it was patched with malware :)
Not growl as in death metal vocals.