You can do further training on them, just like you can patch a binary blob. There are some surgeries you can do to the weights, and there are analyses you can d

You can do further training on them, just like you can patch a binary blob. There are some surgeries you can do to the weights, and there are analyses you can do to poke at them and try to understand them, but ultimately they weren't created from a human understandable spec, and without a ton of reverse engineering work the weights by themselves aren't human understandable: hence the "source" component is missing. The source code that generated the weights is one step removed from the kind of source code we'd need to interpret a bunch of AI weights. It's really meta-source code