This was invented by a freind of mine to reflect the type of thing another freind of mine, max, who thinks he is Jamaican, might say instead of safe.
It stems from when max met a UK MC called Demon, and is designed to illustrate what max might of said to try and impress him with his Jamaicaness (By sticking ting on the end of safe makes it sound more jamaican).
Since then it has caught on and is now widely used in the Hertfordshire area of UK.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.