The array is the list of functions that you pass in, like how I did on the demo page (index.html).  I didn't want to limit what could be done with them, in the event that someone wanted to fire multiple functions on a callback, and didn't want to limit it to just what we need (i.e. displaying a login modal if the state is inactive but a snippet is clicked).  If you wanted to do just one function, then you could pass it in like on the demo page, or you can just put the callback code in the array.

I can't really think of when someone would overwrite the callback setting without reinitializing the snippet, which would reset everything anyway.

My logic for firing them on the snippet is because there were already click events on the snippet.  I figured that it would make more sense to handle the click events together in one place.