I'm not really sure what you're proposing I could even do to address this issue, that I should be having Asuka go "Huh, my reflection sure looks weird, I suppose I should look at my reflection more" or something in that line? That would be really weird and tacky and completely ruin the thing. I really don't know how else to present something like that other than completely break the immersion of the player or put a tutorial box, which would eliminate the whole point of the room in the first place.
Honestly I feel that part of horror games, especially retro horror games like Clocktower is trying to figure out what to do and what's the sollution to the problem, even when they're vague. This is meant to be a retro horror game and emulates that unknowing factor of what you can do.