In the story of Narcissus and Echo he tells the story of a man who is so preoccupied with his own beauty that he condemns another woman without knowing. Echo helped a bunch of nymphs escape so she was punished by Juno. Juno took away her ability to speak coherently and not only repeat what she has already hear. At this point Echo still has a body and isn't just a rambling voice. Echo sees Narcissus in the woods one day and attracted to him she follows. Her inability to express herself in conversation confuses and enrages Narcissus. Their conversation embarrasses her so much she runs for the mountains where her body wastes away and is nothing but a voice now. If Narcissus had realized that Echo had her speech problem in the beginning he may not have brought her so much shame that she allows herself to be exiled.
I think that Orpheus and Eurydice is a story about making deals with the devil and also not trusting your partner. His wife does and he mourns for however long he thinks is appropriate and then immediately goes and tries to make a deal to get his wife back. The only thing he has to do in order to bring Eurydice back is to walk away without looking back at her to see if she is following. He can't do it. He looks back and Eurydice is forced to die twice. If he had trusted her completely he wouldn't have looked back and they would have gotten to start all over again. He trusted the governor of Hades more than he trusted his wife. His mistake lead him to live a miserable life in the mountains alone.
The most confusing tale of all of them is Pygmalion's. He wants a woman completely pure of any kind of indecent, inappropriate behavior so he creates a fake woman. He worships this fake woman so much he even buys her clothes, jewelry and showers "her" with gifts. Rightfully so he calls her his Ivory Maiden. I think the Ivory maiden part represents the statues pureness and chastity. He asks the goddess to make her human and it really does happen. What I don't understand is why does he get everything that he wants? He is worshiping a statue that is so unlike anything on earth it's almost a goddess itself. Is it because he does so with such unwavering commitment? I can't really understand the lesson or human flaws with his story.
I think Ovid's stories are little tales to explain a fault or flaw in the human race or to tell stories of warning. I think they do so pretty well except for the fourth story that seems to be missing the underlying meaning that the others have.