From the web page:
Blockly is a web-based, graphical programming language. Users can drag blocks together to build an application. No typing required.
This proposal or something quite close to it has potential for a graphical subject identity or merging language.
Or does it?
You hit the wall with graphical, rubber-ducky sort of languages when you need a block that hasn’t been specified.
Doesn’t bode well for a general visual subject identity language. Possible for a specific domain.
Types of motor vehicles, air or water craft by outline for example.
Perhaps the most common subjects could have icons, supplemented with a small number of pre-defined key/value pairs.
Could work, would depend on the domain and skill of the users.