There are basically four types of "E-Bikes" out there... Legal, where the motor won't help above 20Mi/32Km throttle only, legal where the motor won't help above 20Mi/32Km PAS only, Legal with both PAS and throttle and the motor only helps to 20Mi/32Km... and illegal where the motor helps to go faster than 20Mi/32Kml. It's the illegal that gives E-Assist the bad rap, IMO... Any legal E-Assist bike ridden in PAS can't really be distinguished from a "normal" bike that is ridden as one would any bike... It's the person riding the bike that defines how it can be perceived by others in general not the type of bike itself... JMO

EDIT; If it looks like the bike is going faster than it can normally be pedaled, it's more than likely illegal, and if the person is not pedaling than it's more like a moped/motorbike than a bicycle...