S, M, L

Quick note: I think in a user interface, objects should have at least three different sizes, or semantic zoom levels: S(mall), M(edium), and L(arge).

In a files-and-folders GUI, S would be the icon, M would be the opened file or folder, and L would be the details/properties dialog of a folder or file, showing even more information.

In a REPL, M would be the normal size for evaluated objects. Sub-objects, e.g. member variables would be displayed as S. Inspecting an object switches it to the L setting.