Boo fucking hoo. I hope I never have to work with someone that petty, self-centered, weak, and unprofessional.
Also, you're an intern and she's the boss. So shut the fuck up and buckle up, buckaroo, because it's a tough world out there and it doesn't revolve around you. When you have a show of your own you can make the rules, including barring your wretchedly unhappy employees who would rather be working for anyone else from saying the dreaded MC words. Until then, shut your piehole. And if you're too stupid to figure that out, well, you were hired for exactly the reason Cummings explains here:
You just know this person was angling for a big payday from their deep-pocketed network. I can just imagine that conversation. "My boss wished me a Merry Christmas and now I'm too traumatized to work. But for the right price I think I can find a way to cope and feel better enough not to get a lawyer or make a big deal about it on social media."
I hope Cummings incorporates this into her next stand-up routine, because it's just that hilariously pathetic and laughable. Also, I'd love to know if that intern showed up for work on Christmas or accepted any gifts or bonuses, because, it's just another day, right?
It must be miserable going through life so miserable that that's what you complain to HR about. Seriously, this loser isn't going to make it in the real world if someone saying, "Merry Christmas" at Christmastime gets their panties in a wad.