She got to her interpretation by reading Eugene Peterson's translation in The Message. Here it is, see if it doesn't help make sense of why Mark includes it (and moreso why the lectionary folk gave it its own week in Ordinary Time).
14King Herod heard of all this, for by this time the name of Jesus was on everyone's lips. He said, "This has to be John the Baptizer come back from the dead—that's why he's able to work miracles!" 15Others said, "No, it's Elijah." Others said, "He's a prophet, just like one of the old-time prophets." 16But Herod wouldn't budge: "It's John, sure enough. I cut off his head, and now he's back, alive." 17-20Herod was the one who had ordered the arrest of John, put him in chains, and sent him to prison at the nagging of Herodias, his brother Philip's wife. For John had provoked Herod by naming his relationship with Herodias "adultery." Herodias, smoldering with hate, wanted to kill him, but didn't dare because Herod was in awe of John. Convinced that he was a holy man, he gave him special treatment. Whenever he listened to him he was miserable with guilt—and yet he couldn't stay away. Something in John kept pulling him back. 21-22But a portentous day arrived when Herod threw a birthday party, inviting all the brass and bluebloods in Galilee. Herodias's daughter entered the banquet hall and danced for the guests. She dazzled Herod and the guests. 22-23The king said to the girl, "Ask me anything. I'll give you anything you want." Carried away, he kept on, "I swear, I'll split my kingdom with you if you say so!"
24She went back to her mother and said, "What should I ask for?" "Ask for the head of John the Baptizer." 25Excited, she ran back to the king and said, "I want the head of John the Baptizer served up on a platter. And I want it now!" 26-29That sobered the king up fast. But unwilling to lose face with his guests, he caved in and let her have her wish. The king sent the executioner off to the prison with orders to bring back John's head. He went, cut off John's head, brought it back on a platter, and presented it to the girl, who gave it to her mother. When John's disciples heard about this, they came and got the body and gave it a decent burial.
The other piece of all this comes from a convention friend named Marcy. She is quick to point out the larger context of this story - the gap between the sending of the 12 and their return with stories of healings and exorcisms. The kingdom of God is alive and kicking in some places, but at this birthday party of Herod's, well the kingdom of the world is showing its muscle too.
Good stuff. Thanks for all the help everybody. Keep the thoughts coming.