Main image and variation in editor - is it a bug?

Hi
I noted this strange behavior.
If a product has some variations, in the Designer I see the “main image” field, but in the editor I the “main Field” field is missed and see only the variations with the main image set for each variation.
This happens even if in the designer the variations don’t have any image.

The result is that the client, using the editor, is not able to change just the main image if the image doesn’t change for the variation.

I hope I was able to explain well.

It is a bug or something else?

Thank you so much.

Nobody else experienced that?