[Answered ]-How to reload certain web images, but not from cache, in Django application?

What you can do is simply put a query parameter after the image so that it will cause the cache to be reloaded :

<img src="{{ MEDIA_URL }}photos/approved/{{ username }}/{{ username }}_thumb.jpg?v={{ username.updated_at }}" />

In this example I suppose you have an updated_at field which correspond to the datetime of the last update of you model.