I haven't read it, refuse. However assuming the gist, I would say that anything you do that you could pay someone else to do "as their job" satisfies the criteria of a SAHM being seen as a job.
So you pay cleaners, child minders, gardeners, window cleaners, taxis, tutors etc etc etc. They are all jobs, paid for and taxable. The only difference is a SAHM is not paid, she is therefore a volunteer, and should be recognised as being a valuable support to society 😉