I've implemented an extension to the [[MediaWiki:Bad image list]] feature. You can now specify a list of exceptions, i.e. articles where the image is allowed to be displayed inline. The typical format is:

* [[:Image:Penis.jpg]] except on [[Penis]]

The text "except on" is ignored, it is not special. Only the links are relevant.

I've documented the format at:

http://en.wikipedia.org/wiki/MediaWiki:Bad_image_list

-- Tim Starling