This is actually 1 bug and a question

Bug:

The Article with files template uses the wrong icon URL.  It uses attachment.icon and should use iconUrl instead.

Questions:

The Post has an almost identical set of attachment variables, except that the attachment.* and image.* variables use the first attachment, and the Article uses the last.  The second difference is that in the attachment_loop, the icon url is icon, and the Article uses iconUrl.