^ Keith grinning? Looks more like a sneer to me. And that "grin" from Mick, such that it is, looks a bit rueful, spiteful even. His mouth may be grinning, somewhat, but the eyes tell a different story. Actually, none of them appear particularly happy to be there. The closest thing approaching an uncomplicated grin is Charlie, but he would be grinning a bit, as he was, uh, medicated.
Even the normally irrepressible Ronnie looks world weary--those Dirty Work writing credits should have made him happy and buoyant. It was an ugly time for the band.