The output goes into the text field where I'm editing. That's not a REPL. Usually printing output to a random text field makes no sense. It can make sense to execute commented code snippets in code, or evaluate code and have the result being inserted.
A transcript window is usually a text output window, more like a console output. I'd say the Workspace window is slightly similar to a REPL. But it still does not work like the usual Lisp REPL, where you type to the tool usually textually at the bottom and get the result displayed there. With Smalltalk I usually type to an editor Workspace window and REPL I/O does not need to have a sequential order.
You're right Workspace window not Transcript, I always mix the name of them.
Still, it looks pretty much to the Lisp Machine demos I know of.
One can choose to evaluate, or evaluate and print.
The 'L' is the whole Smalltalk environment, as anything that changes the environment is kept in memory or saved along the image on exit.
A Lisp like REPL is available as Transcript windows.