This sign was situated in an escalator in a downtown Helsinki shopping mall. Dogs should not be taken to the narrow escalator, which is an obvious security risk, but what makes this striking is the choice of the dog depicted. The most adorable little dog you ever saw, looking right into you with their puppy eyes.
Normally a direct eye contact in a dog-sign would be signaling a threat or maybe active monitoring, but with the selection of such a cute dog breed this is clearly not the message here. To me the eye contact of this dog signals some level of concern (by the dog). "I hope you noticed that this might be dangerous for me?" This interpretation is also supported by the adjacent "No babies in strollers." sign - the purpose is not to forbid something unwanted, but to protect delicate beings from getting hurt in the escalator.