User blog comment:Rupert Giles/Introducing Curated Main Pages/@comment-24431687-20150913035238/@comment-5917596-20150914214135

Azending If the mobile code was updated then the box for a image could be hidden and the text could become a link or some default images could be supply for when no image is available.

Milkandchocolate have you thought about uploading a plain white image to use when you don't have one that reflects your pages/category? that could work as a workaround for you.

https://commons.wikimedia.org/wiki/File:Solid_white.svg