What is the meaning of this short story?

Question

Our Last Fremstad Story

Any tale is anticlimatic after The Farewell, we ought to look i on (Olive) Fremstad as voice teacher, the occupation she took up, like many of her colleagues, upon her retirement. Fremstad was not a gentle coach. Only those with a spirit of iron could survive her course, for training included viewing the inside of a mysterious box that sat on the piano under a red silk scarf.

One day, Fremstad was about to unveil the secret for her secretary to see when a student showed up for a lesson.

"Don't!" the student screamed in terror. "I won't look at it again. I'd rather leave forever!"

"Leave then, poor child." said Fremstad. "Better now than disappointment and heartbreak later." Turning to her secretary as her student fled. Fremstad added, "She has no guts, that one. Opera is not for her." Then she showed the contents of the box to the secretary.

It was a human head, pickled and sliced in half from cranium to neck.

Answer 1

My take on the story is that Ms. Fremstad felt that the demands on the psyche, that would be placed upon an opera singer, were such that exposing them to such a horror would weed out the ones not iron-willed enough to survive the disapointment and heartache of living the life of an opera singer.