This immediately reminded me of the technique my mother adopts when icing* a christmas cake. Corner flourishes acquire flourishes, themselves featuring flourishes (until a round cake really does develop corners), the overall effect strongly resembling this limestone exposure, if not necessarily in permanence (though rock-hard royal icing, without glycerine, is her favourite and mine).

*: 'Icing' is what American confectioners call 'frosting', though in the context of my mother's christmas cakes the UK term is more accurate: it's not a light coating of sugar, a mere decoration on a cake, but a fully self-supporting casing. It may or may not contain a cake at all; verification requires a bread knife and a vigorous sawing action.