This could be summarized as:
"You can use XMLHttpRequests to send more code, and then eval it."
It's a good idea, and can work pretty well in practice.
Do things like this really need to be called out and given pattern names etc though? :/ Patterns suck.
When they restrict the way people think, that's bad. I don't think that good programmers tend to fall into that trap, though. Instead, patterns are simply abstraction, and naming a pattern is simply giving a name to the function or macro or whatever that you're defining.
I guess the difference is that patterns tend to require humans to duplicate the abstraction manually, which does suck. But that's what you get for using a poor programming language. :)
In this case, the 'pattern' could be implemented by a function call, I think. I believe you should use a language where this is always possible. (Does such a language exist?)
It's a good idea, and can work pretty well in practice. Do things like this really need to be called out and given pattern names etc though? :/ Patterns suck.