When Rails adds a large new feature like Active Storage, it takes some time before good Internet resources and documentation become available for it. This can be a challenge when learning how to use the variant method for image transformations. Not only does it take a lot of options, but the format of those options isn’t obvious. To make it easier, check out the resources and tips I’ve compiled here:
http://www.carlosramireziii.com/what-options-can-be-passed-to-the-active-storage-variant-method.html