This function allows you to flip a frame on its horizontal centre axis. Everything above the centre of the frame will appear below, and vice versa. But at the same time text will appear mirror-reversed, as everything that was on the left in the original remains on the left. If you have problems visualising the results, just try out the function.
Incidentally: Simultaneous horizontal and vertical mirroring is equivalent to a rotation through 180 degrees.
Except for the axis of rotation, the function works much the same
as Mirror frame horizontally
immediately above.
