Jquery syntax explanation for PubSub Design Pattern

In my quest to grasp better some Javacript and jQuery concepts, I ran accross the following snippet of code.

var o = $( {} );
$.subscribe = o.on.bind(o);
$.unsubscribe = o.off.bind(o);
$.publish = o.trigger.bind(o);
// Usage
$(document.body).on( 'click', function() {
   // ...yadada
   $.publish( 'clicketyClack' ); // Think Rocky Balboa yelling out the window: "Hey yo!"
});

// And some dude listening patiently for Rocky's voice.
$.subscribe( 'clicketyClack', function() {
        console.log("You can't win, Rock");
});

Problem is I don't understand the syntax very well. What does it mean? Are we kind of extending the on namespace with the bind function?

$.subscribe = o.on.bind(o); --> 
$.subscribe = $( {} ).on.bind($( {} ));

From the Jquery API:

.on( events [, selector ] [, data ], handler )
.bind( eventType [, eventData ], handler )

Thanks a lot for your help