Those faces sum it up pretty well.
By the way, /u/therealdiscolando depending on what exactly was going on there, a tail slate is generally held upside down.
Sometimes a tail slate or end slate is filmed at the end of a take, during which the clapperboard is held upside-down. This is done when the clapperboard was not captured at the start of the take due to the camera being set up for the shot in such a way that the board cannot be captured, for example when a specific focus or frame is set up and cannot be altered until the take is complete.
The end of one take and the beginning of the next is the same thing in our production, so there’s no need for it to be upside down. It just has to have the info on it for the editors to find the correct take. =)