We can't do that without separate subclasses that claim them. The (driver) tests are driven from the images. The sample images are for the tests, so whenever we add new code I like to avoid a change to an existing image as a sort of proof that the new code still works with the old image (insofar as the tests would tickle something). I don't really think we need an update to the image in the tree (unless there's a reason in which case we need to handle that case). If you really want to change it, please put it in a separate commit after and separate from any code changes.

> Do you prefer separate commits for such things, or is it less work to do it all together?

A separate commit per logical change please. They can be in a PR together though if they're reasonably related.