File:Fence gate orientation bits.png

4 fence gates facing each other. The left ones were opened from outside the circle, the right ones from within. You have a fence gate that was opened towards you (let's say facing north). After you closed the gate you open it into the other direction. Now the blocks orientation is facing the exact other way (facing south).

Colours:
 * Red: Facing north
 * Green: East
 * Yellow: South
 * Blue: West