I don't think I'm a complete idiot, but I'm unable to work out whether on a toilet with two flush buttons, the larger button denotes 'bigger flush' or whether the button is larger to encourage you to press the smaller, water saving option. Experiments have been inconclusive.
@fesshole You are absolutely describing one of the canonical bad UI situations of the modern world. The clash of representational, Vs behavioural semiotics in UI/UX.
*edit* for clarity: Is the bigger slice of the button denoting a bigger flush, or is the bigger button linked to the smaller flush, and its greater surface area is a behavioural nudge to make it more likely / more convenient to use less water.