Over there, when properly done, they intentionally "pre-mark" those cue objects outdoors first. Until dogs are attracted to it (indication of marking). That is what I heard. "Plop it in a doggy park until it is marked kinda thing" or pretrained "mark that!" dog or two, or at a doggy daycamp or such. So the "dog bathrooms" have the necessary marking scents, probably. Presumably, they simply used a familiar shape used worldwide (generic fire hydrant) to amplify the smell-permission and owner-obviousness.
It's not perfect, but I gotta admit - very creative.
Some minor training may be needed for your pet (permitted indoor "bathroom" areas, often trained in tall apartments elsewhere) since many are trained not to urinate indoors under all conditions. Multiple cues (markings + familiar shape) are done to lessen the potential confusion for your companion.
If you also trained your dog a "use bathroom" signal (e.g. to gently tell your dog to speed up), that also helps.
It is not easy to teach, but highly recommended to teach your pup a "relieve yourself ASAP" signal before you bring your dog to those doggy bathrooms.
That way, you have at least three or more familiarity cues to say its okay to relieve:
1. Premarked object (most important cue)
2. Familiar shape to other commonly marked objects
3. Owner signal for "use bathroom" or "relieve now if you can"
4. Recognition of "doggy bathrooms" as permitted relief (trained by some condo dwellers, essentially the dog equivalent of a litter box)
Then that more easily gets over the "unsure dog" barrier getting the conficting cues (an indoors marked object)
Sure, one may thumb their noses at owners who never give their dogs exercise, but some indoor pets just can't handle -30C blizzards (too freaked to bathroom), so sometimes responsible owners train the "doggy litter box" into their pup, even if they walk 95% of the time. These dogs really quickly understand the public dog bathrooms (shortest or no further training), given the "multiple cues" scenario.
Never heard that this was possible? Google it, some trainers have been able to teach this. Dogs can be trained to pee or poop on request "if they have not yet". It is useful when you are walking past the last patch of snow before stepping onto an asphalt parking lot or entering a vet. Once they recognize the signal, see the pattern (e.g. opportunities dissapear after your signal), they then easily understand it's their final chance to relieve in a while, and your signal is helpful to your sweetie, knowing you are happy when they do it.
It is amazing how some cities/countries have a different dog culture, given different bathroom trainings.