They talk about their process. It involves a whale harness, and divers to do the milking of wild whales.

I’m honestly still wondering if this is an elaborate joke 😆

Edit: from their FAQ:

Is this a joke? No, this isn’t a joke, and we’re here to stay.

Further down the page:

Treating whales ethically and with respect is our #1 priority. All whales participate on a strictly voluntary basis

I’m still not convinced it’s real…