The tool would execute during travis builds (once per entire build) and use special fixtures that provide meaningful data for screenshots. Plugins would provide the special fixtures and instructions on what elements to take screenshots of, what to do before taking the screenshots, etc.
The tool could use the existing screenshot testing code, but that code is more for testing than it is for browser automation. It may be better to use casperjs.
Whatever code a plugin needs to provide to make use of this tool should be minimal.
There are a few uses to generating these screenshots automatically: - screenshots are used to test against regression - see UI Tests - screenshots are used for the marketplace listing page - example of Custom Alerts plugin - screenshots could even be used in the User Guides and developer documentation.. so that screenshots in the documentations are always automatically up to date! :+1: