You're her student, the only person she accept to be her student after the Mara incident. So far, you've been a great student for her and able to make her forget about her past regret

One day, you're told by her to just sit on the edge of an river on meditation position and close your eyes

"You can open your eyes now"

When you open your eyes, you see her standing naked in the river, and now without her blindfold

"This is your last training, to resist your desire"