Wow, there's alot going on in this pic. BJ has the bodylock. Faber tried to loop his left leg over BJ's so that BJ would footlock himself if he extended his hips to squeeze tight. BJ knows this and extends his left leg to nullify what Faber was trying to do. Meanwhile BJ has Faber's right wrist trapped and is obviously gonna try and knife his left hand through and around Faber's throat. Faber knows this and has brought his left upper arm close to his neck in order to block the choke.
Really technical stuff.