Some companies do indeed try and explain the 'non-cash' impact of impairments reported in their P&L and provide 'adjusted' numbers to show the underlying earnings. But for some reason MML have chosen to not 'dress up' their report at all.
But it has hardly been unusual amongst all the PM producers worldwide!
I don't have the time to go through a long list, but here are a few examples of recent impairments from stocks listed on the ASX: