Losing control of her yoga posture.
And I had high hopes! It's unfortunate, but she's gotta figure stuff out. Or something. Here's the PopMatters review, and a couple representative paragraphs:
More problematic is “Smile” and its bold pro-roofie stance. “You know that I’m a crazy bitch,” says Avril. All fine and good, and she helpfully explicates, “I do what I want when I feel like it.” Right! Don’t let anyone tell you what to do, crazy bitch Avril! But then: “All I wanna do is lose control.” A paradox: I lose control when I feel like it. (Know who else says that? ADDICTS.)
This “Smile” paradox can mean one of several things. Maybe Avril is a control freak—“I do what I want when I feel like it”—who yearns to break free from her neuroses and lose control. That’s why she smiles when the guy puts something in her drink that makes her black out—she hates who she usually is. Or maybe it means she has no ambition to do anything other than lose control; she doesn’t want to eat or sleep or make music or go clubbing or brush her teeth with a bottle of Jack, she simply longs for the Void. Most likely, the Avril of song simply overlooks the contradiction in the “Smile” paradox and so commits to both impulses. And our job is simply to watch and marvel as these irreconcilable impulses tear Avril’s narrator apart and, if we’re lucky, spot them in ourselves before it’s too late.