nix language: why in some contexts fields can be used recursively and in others not?

I was reading nix.dev/tutorials/nix-language, and it has the following minimal package example:

nix language: why in some contexts fields can be used recursively and in others not?

I was reading nix.dev/tutorials/nix-language, and it has the following minimal package example:

nix language: why in some contexts fields can be used recursively and in others not?

I was reading nix.dev/tutorials/nix-language, and it has the following minimal package example:

nix language: why in some contexts fields can be used recursively and in others not?

I was reading nix.dev/tutorials/nix-language, and it has the following minimal package example:

nix language: why in some contexts fields can be used recursively and in others not?

I was reading nix.dev/tutorials/nix-language, and it has the following minimal package example:

Evaluating `writeShellApplication` results in what? How is closure determined between packages defined in attributes returned by the module system?

Main questions:

Evaluating `writeShellApplication` results in what? How is closure determined between packages defined in attributes returned by the module system?

Main questions:

Evaluating `writeShellApplication` results in what? How is closure determined between packages defined in attributes returned by the module system?

Main questions:

Evaluating `writeShellApplication` results in what? How is closure determined between packages defined in attributes returned by the module system?

Main questions:

Evaluating `writeShellApplication` results in what? How is closure determined between packages defined in attributes returned by the module system?

Main questions: