The “custom image menu Col” it’s just to give a name to that column so you distinguish between the other columns. In this case the options are set not to show that title.
In our example we use one entire column just to show the image, didn’t understand your category explanation.
Or you fill the column with custom html, or you don’t fill and then you will add your desired menu items to this column with the drag and drop functionality.
-Rui