oriel36 quoted Newton:

"For to the earth planetary motions *appear sometimes direct,
sometimes stationary, nay, and sometimes retrograde. But from the sun
they are always seen direct.." Newton

**************

But there is nothing wrong with this statement, it is exactly right.
From the earth we see the planets moving in the same direction
(direct) most of the time, but we see them in retrograde a part of the
time, due to the orbital motions of all involved, just as your
animation shows.

From the sun's vantage point you would never see retrograde, only
direct (normal) motion.

What's so hard to understand about this? Can you reference anyone else
who thinks this is incorrect? I didn't think so...

\Paul