How can a multiple conjunction occur during a retrograde motion?

[Sylvain9595]

Here's an animation that shows clearly the problem :

codepen.io/Boanerges-the-solid/pen/bNewJXQ

How can a multiple (usually double, but sometimes triple) Earth-planet-star conjunction occur during a retrograde loop of the planet when the planet's line of sight (shown in red in my animation) can only be parallel to the star's line of sight (in yellow) once during the transit?