Ann: Shareholder Update - Capital Management, page-89

And they will be used as colateral to secure the interest repayment. So in other words you will lose the lot if you don't pay up. In other words, some holders might not want to convert too early or else if the price goes down towards expiry and they decide its not worth converting them all anymore they will lose what they have already paid for.
Managing and balancing your exposure is the most important thing with this sort of thing if you are going to convert your options bit by bit.
So the company is hoping you know this and that convert all at once to minimse your risk and that you then exit the facility alltogether cleanly.
As soon as you convert your shares under the facility your secured shares are the collateral until the interest has been paid off. As someone else says IMO (in my opinion?) this facility isnt as attractive as doing the converting yourself unless you hold a hell of a lot of options. And that means to me that this really only benefits large sophisocated investors.
So the company is looking for a lot of money in a short time in the next few months. Why? Does it imply something good or something unfortunate? Not so simples.