The monitor is hidden in a box (not shown). Orange screw powered by a motor moves blue slider. The green display support has revolution joint with the slider. Violet cam via pink crank, two pinions and a red rack turns the support 90 deg. at its forward position.
The red rack moves in a runway of the blue slider only when the monitor is turning.
Using such second shaft for the pink crank is needed (instead of green shaft of the support). If not the violet cam will be protruded outside the box.
Replacement of gear-rack drive with parallelogram mechanism is possible provided its dead position is avoided.