Nothing happened. Isaac frowned.
"I said: make me my normal, skinny male self again," Isaac demanded again. Nothing. Maybe it was how her was saying it?
"What if I was my normal, skinny male self again?" Nothing.
"I wonder what I'd look like if I was my normal, skinny male self again?" Nada.
Isaac tried dozens of variations of the command, but none worked. She stay a rather busty, chubby woman.
"Why won't you work?" Isaac demanded.
"I am working," the reflection responded. Isaac stared in horror.
"You can talk?" she asked.
"Yes. I can talk. When necessary, I provide help," mirror Isaac said, monotonously.
"So...why can't I change back?"
"Most changes are permanent," the mirror answered. Isaac's stomach twisted.
"What? Explain!" she demanded.
"This mirror is designed to help women, and men, become their ideal woman," the mirror explained. "Should a man become a woman there is no going back. Regarding your other changes, the mirror only gives you what you want. If you really wanted to be skinny it would help, but you seem to want to be fat so that's what it will do. It is possible, if you are strong willed enough, to get it change you however you want, regardless of your hidden desire, but it tempt and fight you, seeking to fulfill your wishes."
"But I want to be a guy again!" Isaac shouted, almost hysterically.
"That is not change the mirror is capable of," and then it was silent.
Isaac settled her thick body on a nearby chair as she thought about this. She was a girl. She would always be a girl. And worse, the mirror said she wanted to be fat. She knew that couldn't be true, but she could feel. She tempted to tell the mirror to make her ass bigger, to make her thighs thicker, to make her fatter. She wanted it badly. She had to resist it though. Do something. Just keep her mind off the mirror.
What does Isaac, now Isis apparently, do?