Google image search "Pygmalion," and you're going to see a lot of images of a naked female statue standing on a pedestal. That's because the statue of Galatea is the main symbolic image of this myth. Pygmalion believes this statue is the most beautiful woman in the world, and the more he stares at her, the deeper in love he falls. This is a bit of a problem, of course, since, um, she isn't real.
By refusing to talk to real women and becoming obsessed with his statue, Pygmalion creates an unrealistic romantic fantasy for himself. Galatea can't talk, so Pygmalion is free to imagine her personality as anything he wishes. This frozen woman will never disappoint him, since she is incapable of arguing, leaving, or eating the last of the ice cream and not replacing it.
Although few people actually create statutes of their love interests (because it's creepy), we metaphorically do this all the time. For example, have you ever made a list of the qualities that your perfect girlfriend or boyfriend would have? Well, you're constructing a person in your mind who very well might not exist in real life.
Similarly, have you ever had a friend who was totally in love with someone at school, even if they didn't really know that person? They're basically doing exactly what Pygmalion did—worshipping the idea of a person, even if they barely know them.
And that's what people mean when they say, "don't put them on a pedestal." It basically means, "don't think about that person like a perfect statue." As human beings, we all have flaws. But here's the thing: this myth seems to be telling us that creating an unhealthy ideal of someone isn't necessarily a bad idea. Hmmm.
Symbolically, the idea of putting someone on a pedestal is all over our culture. Think of Charlie Brown and his crush on the Little Redhead Girl who he hardly knows. Or all the girls in Win a Date With Tad Hamilton. Or even consider our collective crush on Ryan Gosling. There's no way that guy is as perfect as we think he is… is there?
In high culture (not that Ryan Gosling isn't high culture), the image of the naked, statuesque woman appears all over Renaissance paintings. Even if she isn't explicitly a statue, she poses in a very "statue-y" way, presenting herself as an idealized vision of female beauty. Botticelli's Birth of Venus should give you an idea.