I've now twice watched the new minute-long teaser trailer for I'm Still Here (Magnolia, September 10), Casey Affleck's documentary about a performance art stunt by strange year in the life of brother-in-law Joaquin Phoenix, and the phrase that most comes to mind is "metaphysical wankery." That doesn't mean that's all it is or has to offer, of course, but that's what it feels like right now, from this proffering. Regardless of whether it's "real" or a bone-deep mockumentary, what's the film's through line, that's the question. And if it's the rap career thing, that's a problem. For more information, click here.