ArtefactTypeMismatchException when you try to display a profile icon in an Image block

To replicate:

1. Go to Content -> Profile Icons
2. Upload a new profile icon
3. Go to Portfolio -> Pages
4. Create a new page
5. Put an Image block in the page
6. For the picture in the image block, select the profile icon you just uploaded. (It'll be in the "Images" directory)
7. Save and close the block config

Expected result: The block config closes and you see the image served up.
Actual result: The block config hangs, and this error appears in the server logs:

[WAR] 48 (artefact/lib.php:298) Artefact type mismatch. You are trying to use this profileicon as a image., referer: http://vegas.wgtn.cat-it.co.nz/mahara/ht
docs/view/blocks.php?id=9
Call stack (most recent first):, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id=9
  * ArtefactType->__construct(10, null) at /home/aaronw/www/mahara/htdocs/artefact/file/lib.php:475, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/vi
ew/blocks.php?id=9
  * ArtefactTypeFileBase->__construct(10, null) at /home/aaronw/www/mahara/htdocs/artefact/file/lib.php:1018, referer: http://vegas.wgtn.cat-it.co.nz/mahara/
htdocs/view/blocks.php?id=9
  * ArtefactTypeFile->__construct(10, null) at /home/aaronw/www/mahara/htdocs/artefact/file/lib.php:2219, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdo
cs/view/blocks.php?id=9
  * ArtefactTypeImage->__construct(10) at /home/aaronw/www/mahara/htdocs/artefact/file/blocktype/image/lib.php:52, referer: http://vegas.wgtn.cat-it.co.nz/ma
hara/htdocs/view/blocks.php?id=9
  * PluginBlocktypeImage::render_instance(object(BlockInstance), true) at Unknown:0, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id
=9
  * call_user_func_array(array(size 2), array(size 2)) at /home/aaronw/www/mahara/htdocs/lib/mahara.php:1581, referer: http://vegas.wgtn.cat-it.co.nz/mahara/
htdocs/view/blocks.php?id=9
  * call_static_method("PluginBlocktypeImage", "render_instance", object(BlockInstance), true) at /home/aaronw/www/mahara/htdocs/blocktype/lib.php:715, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id=9
  * BlockInstance->render_editing(false, false, true) at /home/aaronw/www/mahara/htdocs/blocktype/lib.php:641, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id=9
  * BlockInstance->instance_config_store(object(Pieform), array(size 12)) at Unknown:0, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id=9
  * call_user_func_array(array(size 2), array(size 2)) at /home/aaronw/www/mahara/htdocs/lib/pieforms/pieform.php:527, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id=9
  * Pieform->__construct(array(size 15)) at /home/aaronw/www/mahara/htdocs/blocktype/lib.php:996, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id=9
  * BlockInstance->build_configure_form() at /home/aaronw/www/mahara/htdocs/view/blocks.php:72, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id=9
, referer: http://vegas.wgtn.cat-it.co.nz/mahara/htdocs/view/blocks.php?id=9