Are you referring to the scene with Mistress Yuki-Ona or the Headmistress?
The one with the Headmistress is supposed to use the statues at the 'intermediate' level where she commands you, but does not explain what the position should include.
With Yuki-Ona, it may be that we need to disable the statues when you have to 'practice' what you've learned.
Thanks for the feedback!