The speaker and others were keen about Richard Cory. Whenever he was nearby, their attention was on him.
The speaker characterizes Richard Cory as somebody we all dream of being. He’s gentlemanly, clean, magnificently slim; he’s plainly dressed and conversational; he’s charming; he’s richer than royalty and very learned. But all this characterization does is cause a very unexpected ending, which confuses us about whether we truly would want to be Richard Cory.
We must keep in mind that the speaker only knows a fleeting image of Richard Cory. She can only understand what she hears or sees from Richard Cory while he’s downtown, and she is therefore unreliable. We’re all limited to a phantasm of Richard Cory—reader and speaker alike.