Testing Example: Image Galumphing

In software testing, variations (or galumphing) is an important way to increase test coverage, and your observations.
This is just an excerpt, and it won't teach you how to do it in your unique situation.
But it's an example, and it might help...

[@AntoniRoszak]

Would it be possible to upload a HD version of the content? It is now limited to 480p which compromises readability.