The magic trick is that when you click the card to copy it to your clipboard you'll end up with two versions of the clipboard. One will be used when you paste

The magic trick is that when you click the card to copy it to your clipboard you'll end up with two versions of the clipboard. One will be used when you paste into a rich-text aware editor (like google docs). In this case it happens to be an ascii art of the card you chose. The other one will be used when you paste to a text-only editor (like your URL bar). In this case it happens to be the OP's author's twitter URL.