11:34 PM, Tuesday October 19th 2021
It is relatively subtle depending on how deep the box is and where the vanishing point is.
It's a bit like a spinning disk. A spot on the outside edge is travelling more distance than a spot near the centre for the same angle of rotation.
In this case you can think of the near face being the outside dot. That face is turning away from you faster than the furthest face ( the inside dot ).
Not sure if this helps either but I thought of it so I thought I would say it. Perhaps try drawing a really big box with a lot of foreshortening then measure the edges and see if that helps. Good luck.