Probably not, it’s one commit per book. So here’s the commit that added images and alt text for “Flopsy Bunnies” for example: https://github.com/standardebooks/beatrix-potter_short-ficti...

But broadly, it’s a case of exposing the information a reader would be interested in, in a way that’s aligned with both the context and style. So if you look in that commit you’ll see for example a couple of alt texts:

Thomasina Tittlemouse sniffs at a jam pot on which a black fly is sitting. Behind her lie a couple of sleeping bunnies on the grass.

Benjamin Bunnie wakes up and pulls the paper bag up to look out at Thomasina Tittlemouse, who is now standing on the jam pot.

The two images are in sequence and illustrate a short scene, so the alt text reflects the reader’s expected understanding at that point.