Black Lantern Batman has a really goofy look: one hand is bent weirdly, and his tongue is hanging out. Now, either you can imagine him drooling onto his bib while the nurses at the home change his catheter, or you can think of other people who might stick their tongue out - such as, famously, Michael Jordan.
The pose simulates the famous "Jumpman" logo, which you can learn all about here. In fact, an alternate working title for this strip was "Jumpman Begins," but our decidedly unathletic readership would have connected that with Super Mario's original name, not with anything related to His Airness.
The ball and the the net are both from McFarlane's NBA line, and Bats' braindead cry of "hooperball" comes from AOTS segment Time 2 Sports. Squeakin' it up on the hardcourt!