When in the "Resources" list, the option to delete an individual resource is not available--the button "Delete" just isn't clickable. If a user wants to delete a resource, they have to:

1. Find the Workflow run that produced that resource;
2. Delete that Workflow run;
3. Go to the "Resources" list and find the offending resource;
4. Delete the resource.

Demo (wherein you can see that I can't delete the resource at first; it only works when I delete the workflow run):

I have two requests related to this:

1. If a user deletes a workflow run, all of the resources it produced are automatically deleted also. (This is kiiiind of related to this issue rodan allows files that don't exist to appear in avaibable input port resources (idiot-proofing request) #625)
2. Allow individual resources to be deleted both from the "Resources" list and from a workflow run, without the entire workflow run needing to be being deleted.

I think both these things would save users' time, and also be more intuitive.