The painting below is by John William Waterhouse (1849-1917). It depicts an interaction between Narcissus and his lover, Echo. It's a figurative depiction of their moment together, so you must imagine the literal picture. Let's look at it.
How would you describe what's happening? Here you have those two beautiful young lovers, off all by themselves in such a romantic setting. It's even springtime. You can tell by the flowers. Narcissus was hunting, but you can see he's cast aside his bow and arrows. Hmm. I wonder what they could be doing. Hmm.
That's about as intimate a human interaction as there is, isn't it?
Yet who or rather what is Narcissus making love to?
Echo is gazing upon him with a look that needs no words. Though it is wistful, it is to die for, the look every man dreams of getting from his lover. It would make Tarzan thump his chest and give a Tarzan yell.
But what's with Narcissus? What does he see in that look on her face? Nothing. He doesn't even see her face: he isn't looking at it. Instead, he has eyes for nothing but his own reflected image, as in a mirror. Is this guy crazy, or what? Look at her! She's a 10!
Yet Waterhouse shows that he's oblivious to her. He has eyes for nothing but the image of himself he's casting. He's gazing upon it with every bit as much admiration as she's gazing upon him. That's why Waterhouse shows him not even looking in her direction: he might as well not be. He doesn't see her. He sees nothing but the flattering image of himself reflected in her face.
That is, he doesn't see her face: he sees only the expression on it. In fact, Waterhouse is being downright sarcastic, because he depicts Narcissus quite literally "prostituting" himself before his reflected image, making love to it, rather than her. Prostrating himself before it is actually a formal act of worship. Judging from the way Narcissus is acting, he doesn't even know Echo's there. She might as well be that handy pond.
That's humiliating to her. In the very act of making love, he's humiliating her. The sick-o.
Something has gone terribly awry here, hasn't it? While it's normal to be aware of our reflection in the feedback we're receiving from someone, it's abnormal to be totally absorbed in it, to the point that you are unaware of anything else, including that other person.
Notice that Narcissus is performing to get and hold 100 percent of Echo's attention while giving her zero in return. Which means that she is as insignificant to him as an object, a mirror. Indeed, when was the last time you paid any attention to a handy mirror you were just checking yourself out in?
What does this mean? It means that no communion or communication is taking place. No human being communicates with a mere object like a mirror. This is mere intercourse, a one-way street. There is no give-and-take with a narcissist: it's all you give and they take.
And so, remember that attentive people's facial expressions (and other forms of expression, such as tone, gestures, and behavior) are mirrors that we see our current image reflected in. Narcissus can't get enough of his.
Which is to say that he can't get enough attention. So, he can't let anyone else have any.
Whenever he can get away with it, he denies attention to those around him and avoids, blocks, or ignores their attempts to express themselves. If you ask for his attention, he acts as though you're asking for the sun, the moon, and the stars. As if it would cost him an arm and a leg. Normal people often are so perplexed by this that they blow it off as some misunderstanding.
Narcissus is so avaricious about attention that he can't even stand to be in a room where anyone else gets any. Get some in front of him, and you might as well eat before a starving man, flash cash before a penniless man, or wave heroin before an addict in withdrawal: he will attack you for it. Attention has the same effect on his brain as a drug, so the more he gets, the more he needs. And, like a drug, he prizes it far more than any amount of money it may cost to maintain the source of a constant supply.
In a very real way, attention is a drug. Like dope, attention makes people feel good by delivering a "hit" of certain neurotransmitters (chemicals that transmit, or block the transmission of, electrochemical currents) in the brain. Like anything that does this (viz., sex, risk-taking, power), in excessive amounts it's addictive. And, simply because it works, nothing is as addictive as a pain-killer. Hence Narcissus is well named from the Greek word for narcosis.
Attention is his pain-killer.