Even true content/download is not documented to work with images, it does.

So I suggest two things:
1: Change doc to reflect that it supports images:
http://ez.no/doc/ez_publish/technical_manual/3_10/reference/modules/content/views/download
2. Add support for image alias as optional parameter

Use case for #2:
1. You want ez publish to check access to the image
2. you are serving the image to a flash object, and the flash object doesn't understand a couple of the charters ez publish uses in the image / file paths ( Norwegian charters / German umlauts and so on..)