probably a shunting or switching layout.
I've only ever heard it referred to as a "British-style" layout.
i'd call it 'evil' for making a 'wagon turntable' the only way to get onto the pier>>6631
this is usually called a 'terminal layout', 'yard layout' or 'switching layout' in the US, sometimes a 'timesaver' if they don't know what they're talking about. 'shelf layout' describes any generic layout with benchwork that's roughly shelf-depth (1'-2'), not how it operates.
I think "diorama" would apply to a model with limited viewpoints (such as not being able to see behind the scenery), but I'm not entirely sure.
FWIW, the area behind the curtain where stock gets swapped out is known in British practice as a "fiddle yard".