sorl/sorl-thumbnail — pull request #152 by mrooney (2013-04-16 17:02:54+00:00)
Title: explain that you need to use sorl's ImageField for AdminImageMixin

If you are just looking through the docs, and end up at http://sorl-thumbnail.readthedocs.org/en/latest/examples.html#admin-examples, you'll never see the section above explaining the ImageField for models, and I and others on StackOverflow have fun into this. Here's a simple change that makes it clear.