When one observes the phases of the moon he sees the moon's day and night, a shadow from the sun illuminating half of the spherical moon at any one time.
The lunar phases vary cyclically according to the changing geometry of the Moon and Sun, which are constantly wobbling up and down and exchange altitudes as they rotate around the North Pole.
When the moon and sun are at the same altitude one half of the lunar surface is illuminated and pointing towards the sun, This is called the First Quarter Moon. When the observer looks up he will see a shadow cutting the moon in half. The boundary between the illuminated and unilluminated hemispheres is called the terminator.
When the moon is below the sun's altitude the moon is dark and a New Moon occurs.
When the moon is above the altitude of the sun the moon is fully lit and a Full Moon occurs.
This description is highly inaccurate.
Where is the Sun when the Full Moon is visible almost directly above the observer? We can set 15 degrees offset from the zenith.
Q: Why does the moon and the phases look the same to everyone one earth regardless of where they are?
A: It doesn't. The phase you see varies depending on your location on earth. In FET this is explained by the different observers standing on either side of the moon. On one side it is right-side up, and on the other side it is upside down.
Imagine a green arrow suspended horizontally above your head pointing to the North. Standing 50 feet to the South of the arrow it is pointing "downwards" towards the Northern horizon. Standing 50 feet to the North of the arrow, looking back at it, it points "upwards" above your head to the North. The arrow flip-flops, pointing down or away from the horizon depending on which side you stand.
The answer makes no sense. One one hand it says that there are different phases based on the location, but on the other hand, it doesn't justify nor answer why would they vary. The answer focuses more on rotation of the Moon rather than phases. One can say that 1st quote describes phases, but... The phase is basically the same across the Earth. So what kind of wizardy makes visible phases the in FE "model"?
Also, how a Moon can maintain its phase (up to very small variation) druing the night?