Author here, it works particularly well for our presented use case because it has these properties:
* There are many files,
* Most of them don't change very often,
* When they do change, the deltas of the binaries are not huge.
So, if the image files aren't changing very much, then it might work well for you. If the images are changing, their binary deltas would be quite large, so you'd get a compression ratio somewhat equivalent to if you'd concatenated the two revisions of the file and compressed them using ZStandard.
