It describes a deep emotional state of nostalgic or deeply melancholic longing for an absent something or someone that one loves. Moreover, it often carries a repressed knowledge that the object of longing will never return.We know this feeling, even if we can't put such a fine point on it in English. It is not just heartache, it is the ache of eternity, of things forever gone, and us forever remembering them even as we would like to forget them. That lover is never coming back: he or she has left you, stopped loving you, is dead, has disappeared. This is saudade. I have inklings of understanding it.
Your see your enemy wearing a bowler hat crossing the street. His bowler hat falls off and is crushed by a passing car. The feeling you have in that moment is Schadenfreude.I used to be enamored of QR Codes, which are 2D tags that act as a kind of glue between two media, like a poster or magazine and a smartphone. A code is specific, often containing embedded information (almost always a URL) that relates to the physical space you are interacting with, whether a billboard or a sign or a page of a magazine. But without integration in a phone's native camera app, they make no sense at all. You have to install and use a separate app, which you must launch and aim at the code. Siri and Google Voice are better ways to find something.