Why can't I find the link in a webpage which does exist in a domain?

When browsing the internet, I found that some files can be hidden from the webpage (I don't know if it's appropriate to say "hidden").

Say I am in a webpage:http://ift.tt/1MHdRzO, and there is no such a link findme (let just call this), at least I can't find it anywhere. But when I google http://ift.tt/1OxS7xK, it does strangely appear. How could this happen? How could it be hidden? Besides, how can I find the names/links hidden after the main domain http://ift.tt/1MHdRzO if I don't know anything beforehand?