It's a Pauline Kael rock star T-shirt, available on Zazzle.com in an endless variety of styles and colors (it looks particularly sharp in eggplant). If the logo looks a wee bit badass for a film critic, that's because Kael was a badass film critic; the design originated on the cover of her long out-of-print 1980 collection "When the Lights Go Down," which includes pieces from The New Yorker on "One Flew Over the Cuckoo's Nest," "Taxi Driver," "Jaws," "Dog Day Afternoon," and many more (you can get a used copy on Amazon).
The shirt was created by another pretty badass film writer: Vern, the "outlaw" film critic whose primary beats are the worlds of action and DTV, and whose own books of criticism include an entire volume on the work of actor Steven Seagal. The Kael shirt comes from a part of his personal website called "Vern's Flea Market," which also includes apparel inspired by "Die Hard" and the works of '80s action screenwriter Steven de Souza. This guy's got great taste.
On Twitter, Vern told me his inspiration for the Kael rock tee: "I saw the book and thought it would look like a great '70s rock logo on a t-shirt." He was correct.