I agree, we should wait for the full promo before we make any final decisions.
I believe that Lady Luck has been around for a long time. If you look at the Queen card from the intro to the site, she bares the same hairstyle. Perhaps she changes appearances every so often with what society considers lucky. Once the queen card was a sign of luck, and now she's moved on to the form of a las vegas beauty that moguls like to keep near them for good luck.
Perhaps even dear old Edgar Allen Poe was a victim of lady luck. He's notorious for having bad luck in life, and even wrote about one of the greatest signs of bad luck. This is all starting to come together storywise, which is why I find it hard to believe people believe there is no backstory.