I think that the magic ingredient is not the image itself. Imagine that you have the language where every method/function is in its own file, and most of them are very short (two, three lines). Then the text editing functionality of the IDE starts to be really unimportant - something on the level of Notepad is good enough. It makes the compilation super fast; the IDE needs to invest in exploring relations between these small code fragments (that have no defined order), their organization, code changes need to be not just text file editing (Smalltalk pioneered refactorings). This is one thing that makes Smalltalk so interesting (and what the mainstream does not get).