Here's my answer, written before reading what the Times guy said:
What should you say? Try speaking like a human being. One doesn't wear a bag, one carries a bag. She's not wearing her new fake bag any more than she's wearing her old fake friend, which is you, Joy, you fake old bag. Think about what makes less sense, her calling her bag Louis Vuitton, or you calling yourself Joy.
And here's what Galanes said:
I’d go with “Nice bag!” But I tend to feel sorry for people who tell (harmless) whoppers. If she felt better about herself, she probably wouldn’t need status items to prop herself up. (Not that there’s anything wrong with your bag collection.) If she really is a good friend, conspiring in a silly lie seems like a lesser evil than dueling over her insult to your intelligence. Or you could give her one of your authentic bags, so she learns the difference.