It's a real legal dodge.
I was 'contracting' for a while with a company. I was employed via a well respected Agency, but what one or two other 'agency' staff were doing was running their payments through another "company", taking a minimum salary, but then taking the rest as dividends. Total loop hole that's been closed a little over the years, but I see it still goes on. Was totally legal, but a right dodge. for me, I thought this was too dodgy, especially as I intended only to contract between permanent employment opportunities.
Most 'director/owners' pay for personal items via the director's loan account, and all sorts of other dodges. It happens, but if HMRC catches you out you really are buggered if it's not done right. The law has tightened up massively.
I suspect many of these high earning celebs. are already set up within a 'media' business of their own, and pay themselves a modest salary with dividends. This is just another 'hole' in this case.
It's not right, but nothing is ever 100% and these folk have enough money to employ accountants to save them a few bob. As an accountant myself, I've seen this loads. I've worked in director/owner companies where the 'owner' get's his house extended by 'staff' (staff time/company materials - lost stock) or the fuel for the directors (taken from a company pump) is accidentally logged against other pool vehicles - it happens.