I'm really not hip

So Jane says to me last night, "You know, those girls you posted a pic of are really young."

"Huh?" I replied.

"Young, honey," she says. "They're under age."

I dumbfounded she can tell the difference between 19 and 21. "How can you tell?" I asked smuggly.

"Because of the big X on her hand."

And I'm so ancient I didn't even pick up on the X, plainly showing... and likely wouldn't have known what it was if I had seen it...