The blue dot at the center is the Earth, and next to it are the center of the deferent and the equant point.
The equant point is connected to the center of the epicycle by a faint green line.
The green dot on the epicycle is Venus.
The outermost circle represents the celestial sphere, which carries the mean Sun and the projection of Venus.
Tap on the canvas (or press Space) to start/stop the animation.
Use the sliders (or ASZX buttons) to adjust the speed and the trail length.