How to make image links appear correct in listings

I was building a system for night watch at boat clubs.
When something unusual was detected, one or more images could be attached to the form submit.
The submit added the data into a Blippa Datasource.
And then this was displayed in a dropdown.
The problem was that the images was not displayed.
The solution was to use :urls after the form field containing the uploaded images, like:

$form:bilder:urls$

And then, in the Block, use :imagelist, like

$iter:bilder:imagelist$