On Saturday, October 25, 2014 3:17:29 AM UTC-6, oriel36 wrote:

The one thing missing was what input the Earth's motion has in these sequence
of images as without the Earth's orbital motion, Venus would move through
those phases quicker from a stationary observer rather than being on a moving
Earth.

Yes, that's correct, since the Earth orbits the Sun in the same direction as
Venus, but (in angular terms) more slowly.

In eight years, there are five conjunctions between Venus and the Sun from
Earth's viewpoint, so the Earth catches up with Venus in its orbit five times.

Thus, from Earth, Venus is seen to go through its phases five times, while a
stationary observer would see it go through its phases thirteen times (5 + 8).

John Savard