What is "toggle development store preview" about

When I run shopify app dev, the terminal show
› Press d │ toggle development store preview: :check_mark: on
› Press g │ open GraphiQL (Admin API) in your browser
› Press p │ preview in your browser
› Press q │ quit

What is that “toggle development store preview” for? seem like no effect when I toggle it, and chatgpt said that it is turn on or off embedded mode

Hi @Geoffrey_Lee

This toggle is equivalent to the Development store preview toggle in Partners. It controls whether the draft version of extensions are used. This flag is automatically turned on and off when app dev starts and stops. While the command is running, changes to your extensions are automatically uploaded as draft versions. This is helpful for testing Functions and other extensions.

-Nick