I huge mound of turd that when freshly deposited into a toilet piles up above the water level, much like the way the South Pacific islands were formed from lava piling up from undersea volcanoes.
This phenomena I more frequently occurs in the newer, low water usage toilets. As an added touch, you can plant a small flag on top of it to claim it as yours.
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.