[Django]-How to add a Snippet Description in Wagtail

The screenshot in the documentation is old (from 2015), and the admin templates and structure of snippets have changed quite a bit since then. The functionality to display descriptions was removed in this commit in 2015.

So the short answer is that it’s not possible to easily replicate this behaviour. If you really wanted to you could override the template that is used to render the list of snippet models, and add the description yourself – e.g. by looking for a particular property on the model_opts (the model meta class) and rendering that.