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Bathroom Faucets: User Interface FAIL
The sink faucet in our motel room worked the way you’d expect:

Grohe sink faucet It pivots left-right to adjust the temperature and lifts to control the flow, which is
Offwhen the handle is parallel to the sink countertop.Evidently, everybody assumes that’s the way the identical faucet handle works in the shower, despite the helpful label:

Grohe shower faucet Did you notice the minuscule red dot below-and-left of the handle or the corresponding blue dot just to its right? Absent the label, those provide all the hints you’ll get as to how the handle operates.
The faucet body & plumbing were loose in the wall, as though many previous people had given it a firm yank to get water out of it.
I’m 3.5 diopters nearsighted and can’t see those little dots. Mary is 2 diopters farsighted and can’t see the label or the dots.
What did they think would happen with different valves having identical affordance?